Port Phillip Heads - Trial of a New Source of Slack/Tide/Current Info

1 year 6 months ago - 1 month 6 days ago #302420 by packo
packo created the topic: Port Phillip Heads - Trial of a New Source of Slack/Tide/Current Info
********** Port Phillip Heads - New Source of Slack/Tide/Current Info **********

For those that have been here before, the new "packo prediction tables" for January to March 2018 have been added to the bottom of this post. Those new to this post may need to read more of what this "citizen science" tides project was about in the sections below:-

************* Intro ***************************************

This long post is aimed primarily at private boat divers who dive the Heads area, and possibly some shore divers operating within 10km of the Heads. It will be of little interest to charter divers, except perhaps that it may help those doing slack-water charter dives to avoid days that might not provide much bottom time for the money.

The PoMC's tides booklet or the BoM's "vic-the-rip" web page seem to be the main "tide info" dive planning tools for the south west corner of the bay. These information sources are intended primarily for shipping and smaller sized vessels down to around 5 tonnes. They lack some information that a diver may want, and may also be a little misleading as to the strength of the streams as far as diving is concerned.

Flood Slack predictions in these tables are usually a minute or two earlier than the "official" tales, and the Ebb slack predictions typically 5-10 mins ahead but on a few days a month may be 15-20 mins earlier. With weather corrections it is all a bit difficult to sort out the reasons for the differences.

My latest work suggests the Packo tables are far better for sites well inside the Bay, but my times for Lonsdale wall may be a few minutes too early. Observations clearly show that on some days water flows both IN and OUT through the heads at the same time, with the slack occurring several minutes earlier on the Pt Nepean side than on the Lonnie Wall. My times (for zero net flow) are somewhere in between.

Maybe later on, the right tweaks for the best slack times can be discovered. For the moment I'll leave things as they are because on certain days the official times have definitely been observed as "too late" - and ain't nothing worse than being too late!


********** Short Slack or Long Slack? **********

In attempting to predict the likely duration of slack water, some divers try to take into account the (misreported) max stream values before and after the slack, and the max and min tide heights before and after the slack. It is a hard assessment to make - and many also forget that the duration of the two streams should also be taken into account.

There needs to be a better way, with more diver appropriate tide/current info being available. This post describes a new source of information that is about to be given a limited launch on a trial basis. This system is designed by a nerdy diver (me!), for other divers of various persuasions. It is a bit technical - but just hang in there!


***** Do You Really Understand Port Phillip Bay's Tides & Streams? *****

Bay Tides and Streams can be confusing, and this has created some dreadful myths about what is actually going on. If you are comfortable that your understanding is ok, or you have read some of my earlier posts and basically agree, then you should skip over the coloured block of italicised text. Those who are unsure are advised to battle through the following block:

The majority of bays, harbours, and estuaries, have a congested "upper part" and a fairly "open mouth". The geography of Port Phillip Bay is exactly the reverse, and this makes for a rather special situation where the "normal rules" might appear to break down. Normally, boaters and divers might expect to use the slightly lazy expression "the tide is coming in" for meaning either of, or both of: "the tide (stream) is inwards" and/or "the tide (level) is rising".

Because of our bay's "reverse build", in parts of the bay the seemingly natural associations of "IN" with "RISING", and "OUT" with "FALLING" do not apply all the time, but for only around 50% of the time. When people are confronted with the real world situations of "IN flowing water" and "FALLING tide levels", or "OUT flowing water" and "RISING tide levels" they can become confused.

The path to clarity is to break the bay into two separate parts, each of which has different properties and behaves differently. Our "upper part" (all parts north of a line between St Leonards and Rosebud) is very wide and open without any congesting features. Our "mouth part" or "SW part" (any areas southwest of the St Leonards-Rosebud line) has a very narrow entrance and enormous areas of shallow sand banks (collectively called the "Great Sands").

It is very important to realise the "upper part" contains around 90% of of the total area of what is by any standard, a very large bay. This area is so huge that even a raging flood stream running through the Rip for 6 hours can only fill the "upper part" to just 40% of the maximum ocean level. It also means that the "upper part" high tide will occur some hours later than the ocean high tide because water can still flow inwards well after the ocean level has begun to fall.

Note that the un-congested "upper part" has tides that are fairly uniform in both height and timing. Despite its large size, it can be accurately thought of as a single large body of water, with its High or Low tides occurring a little over 3 hours later than at the Heads.

In contrast the "SW part" has high tides that vary in both height and timing depending on the exact location. Those locations near to the border with the "upper part" have tides with around a 3 hour delay. Sorrento tides have a 2 hour delay. Queenscliff tides have a 30 minute delay.

Essentially the much smaller "SW part" is really best considered as a small "narrow channel", connecting two large water bodies. At any point along this channel, the time of high tide there will be influenced by the high tide times in both water bodies. The closer water body will have the most influence, but the furthest water body also has some say.

The key to understanding tide streams in the bay is to realise these are determined almost entirely by the rate at which the tide in the (90% area) majority "upper part" rises and falls. Contrary to some myths, the current throughout all parts of our "narrow channel" ("SW part") will always be either: "IN" at the same time everywhere, or "OUT" at the same time everywhere, or "ZERO" (slack water) at the same time (nearly) everywhere.

Yes, at the Rip end of our "narrow channel" there will be times during the "IN" flow of water, where the tide height is going "DOWN" (because the nearby ocean has fallen a lot). Similarly there will often be times during the "OUT" flow of water, where the tide height goes "UP" (because the nearby ocean has risen a lot). Near the Rip, these confusing situations occur for a total of about 50% of each 24 hour day. You are bound to experience them.

For the other 50% of the time we have the more natural associations of "IN=UP", and "OUT=DOWN", as would be experienced in the majority of Australia's bays, harbours, and estuaries (for close to 100% of the time). As we move towards the border with the "upper part" of the bay, the "50% abnormal" situation progressively shrinks to "0% abnormal".

Note that in the "SW part", you can't reliably infer which way the current is running from an observed change in tide height, nor can you reliably infer which way the tide height is changing by observing the direction of the current.

Do the tides in the "SW part" play any role at all in determining Rip current? Yes, they do play a small part. The rise and fall of the tides in the "SW part", combined with its relatively small surface area, contributes up to about 0.6 knots of Rip current. Usually it is quite a bit less because as we have seen the tides are mixed here, and often some parts have falling tides while other parts have rising tides. This small component is mostly dominated by the Rip current contribution (up to 6 knots) due to "upper part" tide level changes.

The effect of the small "SW current" is felt when the "upper part" tide height reaches a maximum or minimum. At this time there will be no "upper part" Rip current component, and so it will be slack water at places like Rosebud or St Leonards since no water is flowing past these points because the "upper part" tides are neither rising nor falling.

At this time during flood slacks, the Rip tide level will be falling at its most rapid rate, while areas further east will have only just started to fall. All up, the -0.6 kn "SW part" current contribution will then be the total Rip current. This means an ebbing flow, and that slack water at the Rip has already passed, having occurred some time earlier than slack water at Rosebud.

How much earlier? We can easily calculate that at around just 10 or so minutes earlier, the "ever so small" last of the rising "upper part" tide would have produced a +0.6 kn component, which would cancel out the -0.6 kn "SW current" to give "slack water" at the Rip. If you are suspicious of calculations, then any experienced Rip diver should be able to confirm that near slack water, the rate of current change is roughly 0.5 kn per ten minutes for the whole of the diveable part of a current reversal.

Alternatively, you know typical slacks last 30 minutes as the current changes between the "stay put" diveable limits of +0.75 kn to -0.75 kn (a 1.5 kn change in 30 minutes or 0.5 kn per ten minutes). So what I am saying is that a -0.6 knot contribution from the "SW part" tide level changes, can at best pull the slack water time at the Rip roughly 12 minutes earlier than slack water at Rosebud.

(Note that if you have ever experienced a 20 minute "slack shift" due to the weather, what that actually means is that the "weather current" component superimposed on the normal tide was about 1 knot. In severe storms "weather currents" of up to 3 knots occur. These can shift the slack around by well over an hour.)

The usual "rate of current change" varies between 0.25kn/10 mins and 0.6kn/10 mins depending on the particular tide cycle. In general this means the delay in slack water at other places in the bay compared to the Rip will be between 5 and 20 minutes at the more remote locations, depending on the particular tide cycle.

A small band of "myth men" (astonishingly mostly "experienced" divers & boatmen) totally disagree with this view and have some of their own (very weird) views on how tidal streams in the bay work. Despite a huge effort on my part, I have (so far) been unable to convince this group they are simply wrong. In opposing my stance, they also oppose: PoMC, Sea Pilots, National Tide Unit, and all currently operating Charter Boat Captains, etc. Not sure what on earth is going on in that camp?

Please rest assured, I do know what I am talking about, and you might find the rest of this long post useful if you choose to plough on.



********** Packo's Bay Model **********

The model does not use any complicated bathymetry, and so cannot predict currents at specific locations like professional computer modelling can. Rather it looks at the tide curve predictions of a number of bay sites and tries to compute how the volume of water in the bay changes with time relative to its mean sea level volume. It does this by taking into account how the surface area of the bay is distributed, and what the appropriate tide curve is for each "zone" of surface area. The zones were allocated largely by "common sense" but of course some "guesswork" was also involved. Hopefully the model might be improved as experience gradually allows some "zone tweaks".

Once the bay's "volume curve" is obtained, the times of the maximum and minimum bay water volume points will give the two slack water times for that tide cycle. By looking at how the bay water volume changes with time, the volume flow rate of water through the Rip is obtained. By estimating the cross section of the Rip, this can be used to turn volume flow rates into estimated current-time profiles through the Rip. Useful information for scuba divers can then be extracted from these predicted current profiles.


********** Slacks - How Does The Model Perform? **********

From the beginning there were some differences between Packo times and PoMC times. After much testing it has been established it is mainly the PoMC times that have by far the largest errors. This has been bought to PoMC's attention and hopefully a fix will arrive for 2018. Because of weather effects which can shift the time of slack water around, it can be hard to establish the accuracy of any predictions to better than a few minutes. So far I have no reason to doubt that errors in my predictions are any larger than 3 or 4 minutes.

The predicted slack water times are also given relative to the closer of Sunrise or Sunset. This might either help for planning night dives or checking how high the Sun will be at Slack Water. Elsewhere in the table is a "d" marker to help you quickly identify daylight slacks


********** Streams - How Does The Model Perform? **********

As far as maximum stream flows are concerned I can match the BoM website values to within around 5% by using different scaling factors for the ebb and flood flows. The predicted times for the peak flows usually agree to within 15 mins, with occasional slightly larger errors.

The different scaling factors needed to get close agreement also confirms that the PoMC/BoM is "under reporting" flood stream strengths to the tune of about 75% compared with the actual volume throughput rates. For releasing results publicly I will be using a single scaling factor, so the "currents" reported for floods and ebbs will represent a true measure of the predicted volume flow through the Rip without any "jet effects", "ebb stream shallowing", or "under reporting" of floods. These values will of course be a little different to the PoMC/BoM values.

In viewing current-time profiles around the maximum flows, I see they come in all sorts of shapes. This is due to the tide curve predictions themselves being built up from over a 100 different components, each linked to some aspect of the Earth-Moon-Sun system. I see little point in giving the time of maximum flow as PoMC does, but instead have chosen to give the maximum rate, and the two times between which the current is above 75% of the maximum rate. This might be more useful for boating. The duration of the stream is also given. This might be just for general interest, or it might help in planning days where both slacks are dived.


********** Predicting The Duration Of "Slack Water" Periods? **********

Of course the main purpose of building the model was to try to get a handle on "slack duration" times. Because this will vary for different sites at different distances from the Rip I had (and still have) doubts about the best way to present this information.

In the end I have opted for several different ways. The first is an average "rate of current change" (or stream acceleration) expressed as: plus or minus some fraction of a knot change per ten minutes. Some will find this a strange value, and strange units to use. However adding this number to the current at any particular time, will give a current estimate for 10 minutes later. Working in ten minute blocks seems more suitable for any rough mental arithmetic needed while bobbing around in a boat.

Naturally the bigger the "rate of change" number is, the shorter the slack will be. It should help to quickly sort out long and short duration slacks. Note the sign ahead of this number is NOT the current direction, but the direction of a change in current. So for a flood stream, whose current has a "+" sign, the rate of change will have a "-" sign meaning either the flood stream slows down by that amount every 10 minutes before slack, or the "-" ebb stream after slack will speed up by that amount every 10 minutes.


********** Stream Deceleration/Acceleration Roughly Constant **********

People might be surprised that this value is reasonably constant for the hour or so that spans the slack. Note the incorrect, but common view that a Rip tide stream fades in strength because the ocean and bay levels equalise, would in fact give a decreasing "rate of current change" as slack water approaches.

The common view is simply not true. It is definitely the case that the streams are brought to a fairly abrupt halt (considering the huge mass involved) by running up a "hill" that grows to roughly 30-40cm high at slack water. This hill is created primarily by changing ocean levels.

The water's amazing hill climbing ability is courtesy of its momentum, because at the time when bay and ocean levels are briefly equal, the stream is still running at about 30% of its maximum rate. As the water slows down as it begins to climb, the friction over the bottom decreases quite rapidly. It is then the uphill climb itself that is mainly responsible for slowing and stopping the stream over the last 40-60 minutes of its 6 hour run.

A common situation that is a good analogy to the reversal of the current at the Rip is throwing a ball up into the air. The opposing gravitational acceleration first acts to slow down the ball's upward speed (at the constant rate "g" = 9.8 m/s/s) until the ball's speed is zero ("slack water"). The ball then gains downward speed (at the same 9.8 m/s/s) as it falls.

The difference of course is that in the Rip, the scenario is played out in "super slow-mo", at roughly 1/23,000th of the speed of the ball's reversal. We could slow the ball case down to very close to the timing actually seen in the Rip if instead of throwing the ball up into the air, we rolled it up a very slight (frictionless) uphill slope with a gradient of 1 in 23,000.

Note that [g=9.8]/23,000 (m/s/s) = 0.000426 (m/s/s) = 1.53 (m/s/hr) = 2.8 (kn/hr) = 0.47 knots per 10 minutes. This is typically close to what we observe in and around the Rip for the higher tide cycles.

We also note that the tide gauge network shows that at flood slack water, the water level at Queenscliff is around 20cm higher than at the Rip. The distance between these two points is roughly 4,700m. An estimate of the "up-slope" of 20cm in 4,700m comes in at, wait for it: 1 in 23,500.

So we see that all the number's seem to point in the direction that all this stuff is a reasonable view of how slack water occurs in the Rip. The fact that the "rate of change" number is roughly constant is precisely why current reversal near the Heads is such a relatively quick and savage affair (to the surprise of many!). Being close to "constant" for an hour or so during each stream reversal is also useful for predicting how fast things will change over the Rip diving "window" and beyond.

Apart from the "rate of change" number for different tide cycles showing which slacks might be longer than others, it might also help predict (once at the site) whether the slack is running to schedule or not due to weather effects. If you can measure the current on arrival, then using this number may allow you to "guesstimate" how long before the stream will stop. Or more helpfully, how long before the current is low enough to "drop in".


********** Acceleration Values - Not Quite Constant **********

While the analogies of the ball thrown in the air, or rolled up a slight slope are useful everyday examples of motions under a constant acceleration, Rip currents only approximate this behaviour. During the diving period the retarding "hill" does change a little in height. Also the peaking tide curves in the north are sinusoidal curves, not parabolic "constant acceleration" ones. And as well for certain tide cycles the current component due to changing tide levels in the "SW part" is also not accurately constant, so this also needs to be factored in.

Adding all this together we see that although the "rate of change" number is "usefully constant" over a diving period, the numbers for the "before slack" and "after slack" are often a little different. Usually this difference is not that much, but for some tide cycles the "after slack" number can be somewhat higher. This means the stream "build up" after slack might be significantly faster than the "slow down" was before slack. Days when this happens, can catch divers unawares.

To provide a warning of such days, my second way of giving slack duration is to give both a total number of minutes for the slack, followed by a breakdown of "minutes before" reversal and "minutes after" reversal. Be cautious where you see the "minutes after" number being much smaller than the "minutes before" number. (Note that on rare days, weather effects can also bring about a fairly sudden end to a slack - care is needed at all times.)


********** My "Brave Calculation" Of Slack Water Duration In Minutes **********

How are these "minutes duration" calculated? Well it is a brave man indeed to commit to a "number of minutes". These are estimates only, and will no doubt need to be revised in light of feedback. Remember I didn't initially want to speak "minutes" at all, but that is what divers really want - so I thought I would give it a try!

These values assume a dive site somewhere in the Pt Lonsdale - Pt Nepean - Shortland Bluff triangle. They are calculated by using the times when my predicted "Rip current" values drop below 0.7 kn for the "old stream" and then later rise above 0.7 kn for the "new stream".

There will many factors that will require you to adapt these minute numbers to your own style of diving. These limits are for my style of diving:- anchored boat and often alone. Bottom times are usually between 25 and 50 minutes only (if the tide permits). I seem to have a good sense of direction and virtually always ascend up the anchor line. I will always terminate the dive once the bottom current picks up to 0.5kn (0.8+ kn on the surface). I simply do not have the luxury of extending my time by drifting off in the current and hoping for a "magical" SMB pickup.


******** What Is In The Tables? *********

The upper "Legend section" outlines what info is in the main body of the "Packo Prediction Table". Clock times are military style but with a colon in the middle and will be daylight savings corrected. Other times (ie. either stream run times, or relative times before or after a sunRise or a sunSet ) are given with an "h" between a single hours digit and the minutes.

Keep in mind the general table layout is "SLACK WATER" info is on the LEFT side of the table, and info about THE FOLLOWING STREAM and TIDE is on the RIGHT side of the table. If you want info about the STREAM BEFORE the slack, then look at the right end of the line above.

cheers,
packo

**************** DATES & UPDATES *******************************
The "packo predictions" below have been updated to cover until the end of March 2018. The next update is due March 22nd 2018 and will cover April - July 2018.

**************** TABLE FORMATS AVAILABLE *******************************

The "plain text format" version of the tables (or just parts of it) can be copied and pasted into any user document. However to maintain the column alignment a fixed pitch font must be used (eg. courier). Some operating systems may copy the font information across to the new document, some may not and the user may have to force a fixed pitch font for proper viewing or printing.

Alternatively below the "text format" version I have added links to a version of the tables presented in a "month-by-month image format". These show correctly formatted jpeg images for each month's predictions. These may be downloaded via the web browser and copied for later viewing. Almost any device can render jpeg image files. The resolution is deliberately fairly high so that older divers with small screen devices can expand up enough to perhaps allow reading without glasses.
BoM required disclaimer:
“This product is based on Bureau of Meteorology information that has subsequently
been modified. The Bureau does not necessarily support or endorse, or have any
connection with, the product.

In respect of that part of the information which is sourced from the Bureau,
and to the maximum extent permitted by law:

(i) The Bureau makes no representation and gives no warranty of any kind
whether express, implied, statutory or otherwise in respect to the availability,
accuracy, currency, completeness, quality or reliability of the information or that
the information will be fit for any particular purpose or will not infringe any third
party Intellectual Property rights; and

(ii) the Bureau's liability for any loss, damage, cost or expense resulting from use of,
or reliance on, the information is entirely excluded."

*********************** JANUARY 2018 ********************

 ----------- PACKO PREDICTION TABLE - PORT PHILLIP HEADS 2018 ----------------------- 
|-----------|-------------------------------|----------------------|-----------------|
| HEADING   | Left side: SLACK WATER INFO   | Right side: STREAM INFO +TIDE+Delay+Dif|
|-----------|-------------------------------|----------------------|-----------------|
| Date/Moon | Weekday_Date_Month. Age of the moon in days. Major phases of the moon. |
| SlkTime   | Slack Times (DLS corrected). Type: F_ = Flood slack, E_ = Ebb slack    |
| wrt.SUN   | Slack time RELATIVE to nearest sun_RISE(sR) or sun_SET(sS) +/- hrs&mins|
| Accln     | Rip current reversal rate in knots per 10mins. NB:sign is NOT flow dir.|
| SlkLngth  | Minutes between 0.7 knots & Slack. Total=BeforeSlk+AfterSlk, d=daySlack|
| MaxKn     | Max Predicted Rip Current (knots) from throughput. "+" =IN "-" =OUT    |
| >75%KnTime| Time interval (Time1 to Time2), when Rip Current exceeds 75% of MaxKn  |
| RunT      | RunTime of the tide stream FOLLOWING this slack. Time in hrs & minutes |
| TideT_H/L | Pt Lonsdale Hi/Lo Time & Height(cm). Last row times may wrap to new day|
| Dly       | Mins Delay to Rosebud Slack. Others: Portsea=30% Sorrento=45% Rye=70%  |
| Warning:- | Divers must ignore "Scuba Doctor's" delay times as they are NOT SAFE.  |
| Dif       | Minutes difference of packo slack times relative to Cardno (BoM) times.|
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| MON_01_JAN F_02:25 sR-3h37 -0.26 52=24+28 |-2.48 03:50-06:12 7h00 04:16  82 11 -07 |
|   Moon:13d E_07:48 sR+1h46 +0.24 60=30+30d|+2.80 09:36-11:54 5h23 10:46 132 11 -03 |
|            F_13:09 sS-7h39 -0.42 31=14+17d|-4.80 14:42-17:48 5h24 16:45  27 16 +02 |
|            E_20:34 sS-0h14 +0.37 37=19+18 |+4.86 22:15-00:36 7h26 00:22 152 14 -08 |
|-----------|-------------------------------|----------------------------------------|
| TUE_02_JAN F_03:40 sR-2h22 -0.32 44=22+22 |-2.84 04:54-07:30 5h28 05:36  81 09 -03 |
|   Moon:14d E_09:08 sR+3h06 +0.24 58=28+30d|+2.92 10:42-13:18 5h05 12:00 136 08 -13 |
|  FULL_MOON F_14:13 sS-6h35 -0.45 31=16+15d|-4.94 15:36-19:00 7h18 17:54  21 13 -04 |
|            E_21:31 sS+0h43 +0.39 36=18+18 |+5.18 23:06-03:00 7h10 01:24 162 17 -14 |
|-----------|-------------------------------|----------------------------------------|
| WED_03_JAN F_04:41 sR-1h22 -0.39 36=18+18 |-3.35 05:54-08:42 5h41 06:42  75 11 -03 |
|   Moon:15d E_10:22 sR+4h19 +0.26 54=28+26d|+3.19 11:42-14:24 4h54 13:06 141 13 -12 |
|            F_15:16 sS-5h32 -0.50 28=13+15d|-5.07 16:42-20:06 7h14 19:00  15 13 -10 |
|            E_22:30 sS+1h42 +0.41 34=17+17 |+5.47 00:00-03:54 7h03 02:24 170 18 -15 |
|-----------|-------------------------------|----------------------------------------|
| THU_04_JAN F_05:33 sR-0h31 -0.45 31=16+15 |-3.81 06:48-09:36 5h52 07:42  66 11 -02 |
|   Moon:16d E_11:25 sR+5h21 +0.30 46=26+20d|+3.53 12:36-15:30 4h54 14:06 147 14 -09 |
|            F_16:19 sS-4h29 -0.45 31=15+16d|-5.18 17:42-21:06 7h07 20:00  12 15 -12 |
|            E_23:26 sS+2h38 +0.41 34=18+16 |+5.61 00:54-04:48 6h53 03:12 175 18 -15 |
|-----------|-------------------------------|----------------------------------------|
| FRI_05_JAN F_06:19 sR+0h14 -0.52 27=14+13d|-4.17 07:30-10:30 6h00 08:42  57 12 -03 |
|   Moon:17d E_12:19 sS-8h29 +0.37 38=21+17d|+4.02 13:30-16:24 5h04 15:00 152 12 -09 |
|            F_17:23 sS-3h25 -0.45 31=16+15d|-5.21 18:42-22:06 6h54 20:54  12 15 -10 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_06_JAN E_00:17 sR-5h49 +0.41 34=18+16 |+5.59 01:42-05:42 6h43 04:00 176 18 -16 |
|   Moon:18d F_07:00 sR+0h54 -0.58 24=11+13d|-4.41 08:12-11:18 6h10 09:36  48 13 -04 |
|            E_13:10 sS-7h38 +0.41 34=20+14d|+4.43 14:24-17:12 5h17 15:54 154 11 -09 |
|            F_18:27 sS-2h21 -0.50 28=15+13d|-5.08 19:36-23:12 6h38 21:48  16 14 -05 |
|-----------|-------------------------------|----------------------------------------|
| SUN_07_JAN E_01:05 sR-5h02 +0.41 34=18+16 |+5.43 02:30-06:30 6h35 04:48 175 17 -17 |
|   Moon:19d F_07:40 sR+1h33 -0.64 22=11+11d|-4.57 08:48-12:06 6h18 10:24  42 12 -05 |
|            E_13:58 sS-6h50 +0.45 31=17+14d|+4.60 15:24-18:06 5h28 16:48 153 10 -10 |
|            F_19:26 sS-1h22 -0.58 24=12+12d|-4.85 20:36-00:06 6h24 22:36  23 13 -04 |
|-----------|-------------------------------|----------------------------------------|
| MON_08_JAN E_01:50 sR-4h18 +0.41 34=18+16 |+5.18 03:18-07:12 6h29 05:30 171 16 -17 |
|   Moon:20d F_08:19 sR+2h11 -0.64 22=11+11d|-4.61 09:24-12:54 6h25 11:12  37 12 -04 |
|            E_14:44 sS-6h04 +0.45 31=15+16d|+4.51 16:12-19:06 5h39 17:42 150 11 -12 |
|            F_20:23 sS-0h25 -0.61 23=12+11d|-4.48 21:30-00:54 6h10 23:24  32 11 -04 |
|-----------|-------------------------------|----------------------------------------|
| TUE_09_JAN E_02:33 sR-3h36 +0.41 34=18+16 |+4.84 03:54-07:48 6h23 06:12 165 15 -16 |
|   Moon:21d F_08:56 sR+2h47 -0.61 23=11+12d|-4.60 10:06-13:42 6h36 12:00  34 13 -04 |
|   3rd_Qtr. E_15:32 sS-5h16 +0.44 32=17+15d|+4.29 17:00-20:18 5h46 18:36 145 09 -11 |
|            F_21:18 sS+0h30 -0.56 25=12+13 |-4.12 22:30-01:42 5h57 00:06  42 11 -08 |
|-----------|-------------------------------|----------------------------------------|
| WED_10_JAN E_03:15 sR-2h55 +0.38 37=19+18 |+4.52 04:42-08:18 6h19 06:54 157 14 -15 |
|   Moon:22d F_09:34 sR+3h24 -0.58 24=12+12d|-4.51 10:42-14:30 6h44 12:48  34 12 -03 |
|            E_16:18 sS-4h30 +0.42 33=17+16d|+4.15 17:48-21:12 5h57 19:36 140 09 -11 |
|            F_22:15 sS+1h27 -0.48 29=14+15 |-3.71 23:30-02:24 5h43 00:48  53 11 -12 |
|-----------|-------------------------------|----------------------------------------|
| THU_11_JAN E_03:58 sR-2h13 +0.34 41=22+19 |+4.11 05:30-08:48 6h13 07:36 149 13 -13 |
|   Moon:23d F_10:11 sR+4h00 -0.50 28=14+14d|-4.48 11:24-15:06 6h54 13:36  36 13 -02 |
|            E_17:05 sS-3h43 +0.38 37=19+18d|+3.96 18:36-22:12 6h10 20:42 136 10 -11 |
|            F_23:15 sS+2h27 -0.40 35=17+18 |-3.30 00:30-03:06 5h30 01:36  64 11 -16 |
|-----------|-------------------------------|----------------------------------------|
| FRI_12_JAN E_04:45 sR-1h27 +0.29 48=24+24 |+3.64 06:24-09:24 6h05 08:18 141 11 -11 |
|   Moon:24d F_10:50 sR+4h38 -0.45 31=16+15d|-4.33 12:12-15:48 7h04 14:24  39 13 -01 |
|            E_17:54 sS-2h54 +0.34 41=21+20d|+3.87 19:30-23:06 6h28 21:36 133 10 -10 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_13_JAN F_00:22 sR-5h51 -0.34 41=20+21 |-2.86 01:30-04:00 5h18 02:24  74 11 -17 |
|   Moon:25d E_05:40 sR-0h33 +0.24 59=30+29 |+3.09 07:24-10:18 5h53 09:06 133 08 -09 |
|            F_11:33 sR+5h20 -0.38 37=20+17d|-4.12 13:00-16:42 7h13 15:12  42 12 +01 |
|            E_18:46 sS-2h01 +0.32 44=23+21d|+3.89 20:24-00:06 6h48 22:36 133 10 -10 |
|-----------|-------------------------------|----------------------------------------|
| SUN_14_JAN F_01:34 sR-4h40 -0.30 46=24+22 |-2.51 02:36-05:12 5h15 03:24  81 09 -15 |
|   Moon:26d E_06:49 sR+0h35 +0.19 75=39+36d|+2.61 08:36-11:12 5h31 10:00 128 08 -10 |
|            F_12:20 sS-8h27 -0.35 40=21+19d|-3.90 13:54-17:42 7h20 16:12  43 13 +01 |
|            E_19:40 sS-1h07 +0.32 44=23+21d|+3.98 21:18-01:06 7h03 23:36 135 12 -11 |
|-----------|-------------------------------|----------------------------------------|
| MON_15_JAN F_02:43 sR-3h32 -0.32 44=22+22 |-2.43 03:42-06:18 5h29 04:30  85 09 -14 |
|   Moon:27d E_08:12 sR+1h57 +0.17 81=42+39d|+2.31 09:48-12:12 5h01 10:54 124 10 -14 |
|            F_13:13 sS-7h34 -0.32 44=22+22d|-3.76 14:54-18:42 7h21 17:12  42 12 -01 |
|            E_20:34 sS-0h13 +0.33 43=22+21d|+4.17 22:12-02:06 7h11 00:30 139 13 -13 |
|-----------|-------------------------------|----------------------------------------|
| TUE_16_JAN F_03:45 sR-2h31 -0.38 37=19+18 |-2.59 04:48-07:30 5h44 05:42  85 08 -11 |
|   Moon:28d E_09:29 sR+3h13 +0.20 70=37+33d|+2.36 10:48-13:12 4h40 11:54 123 12 -16 |
|            F_14:09 sS-6h37 -0.32 44=21+23d|-3.75 15:54-19:42 7h17 18:12  39 11 -05 |
|            E_21:26 sS+0h40 +0.35 40=21+19 |+4.43 23:00-03:00 7h09 01:24 144 14 -13 |
|-----------|-------------------------------|----------------------------------------|
| WED_17_JAN F_04:35 sR-1h42 -0.40 35=16+19 |-2.96 05:42-08:36 5h53 06:48  80 09 -10 |
|   Moon:00d E_10:28 sR+4h11 +0.25 57=30+27d|+2.59 11:42-14:12 4h38 12:48 125 12 -16 |
|   NEW_MOON F_15:06 sS-5h40 -0.33 43=21+22d|-3.82 16:42-20:36 7h09 19:06  36 10 -08 |
|            E_22:15 sS+1h29 +0.37 38=20+18 |+4.65 23:48-03:48 7h03 02:06 150 14 -12 |
|-----------|-------------------------------|----------------------------------------|
| THU_18_JAN F_05:18 sR-1h00 -0.45 31=16+15 |-3.35 06:24-09:24 5h58 07:42  74 10 -06 |
|   Moon:01d E_11:16 sR+4h58 +0.29 48=26+22d|+2.95 12:30-15:00 4h43 13:36 129 10 -14 |
|            F_15:59 sS-4h46 -0.35 40=19+21d|-3.96 17:30-21:24 7h00 19:48  33 12 -10 |
|            E_22:59 sS+2h14 +0.39 36=19+17 |+4.85 00:30-04:24 6h55 02:42 154 15 -11 |
|-----------|-------------------------------|----------------------------------------|
| FRI_19_JAN F_05:54 sR-0h25 -0.47 30=14+16 |-3.64 07:00-10:06 6h00 08:24  67 11 -05 |
|   Moon:02d E_11:54 sR+5h35 +0.32 44=22+22d|+3.28 13:12-15:48 4h55 14:24 133 12 -15 |
|            F_16:49 sS-3h56 -0.36 39=20+19d|-4.07 18:12-22:06 6h50 20:30  31 13 -09 |
|            E_23:39 sS+2h54 +0.39 36=19+17 |+4.93 01:06-05:00 6h47 03:18 158 16 -11 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_20_JAN F_06:26 sR+0h06 -0.48 29=14+15d|-3.86 07:36-10:48 6h04 09:06  61 12 -04 |
|   Moon:03d E_12:30 sS-8h14 +0.34 41=22+19d|+3.58 13:54-16:30 5h06 15:06 137 11 -14 |
|            F_17:36 sS-3h08 -0.39 36=19+17d|-4.19 18:54-22:30 6h39 21:06  31 14 -06 |
|-----------|-------------------------------|----------------------------------------|
| SUN_21_JAN E_00:15 sR-6h06 +0.38 37=19+18 |+4.92 01:42-05:30 6h40 03:54 161 17 -12 |
|   Moon:04d F_06:55 sR+0h34 -0.50 28=14+14d|-3.98 08:00-11:24 6h08 09:42  55 12 -03 |
|            E_13:03 sS-7h41 +0.33 42=22+20d|+3.71 14:24-17:12 5h18 15:48 139 12 -15 |
|            F_18:21 sS-2h23 -0.41 34=18+16d|-4.30 19:36-23:00 6h28 21:42  33 13 -04 |
|-----------|-------------------------------|----------------------------------------|
| MON_22_JAN E_00:49 sR-5h33 +0.37 38=20+18 |+4.89 02:18-06:00 6h33 04:24 162 17 -13 |
|   Moon:05d F_07:22 sR+1h00 -0.52 27=13+14d|-4.10 08:30-11:54 6h14 10:18  50 13 -04 |
|            E_13:36 sS-7h07 +0.34 41=22+19d|+3.86 15:00-17:54 5h29 16:24 141 13 -15 |
|            F_19:05 sS-1h38 -0.44 32=17+15d|-4.33 20:18-23:36 6h15 22:12  35 13 -02 |
|-----------|-------------------------------|----------------------------------------|
| TUE_23_JAN E_01:20 sR-5h04 +0.36 39=20+19 |+4.78 02:48-06:24 6h30 05:00 161 18 -16 |
|   Moon:06d F_07:50 sR+1h26 -0.54 26=14+12d|-4.25 08:54-12:24 6h19 10:48  45 12 -03 |
|            E_14:09 sS-6h34 +0.33 42=22+20d|+3.85 15:24-18:36 5h40 17:06 142 14 -15 |
|            F_19:49 sS-0h54 -0.45 31=16+15d|-4.25 21:00-00:12 6h04 22:48  39 13 -01 |
|-----------|-------------------------------|----------------------------------------|
| WED_24_JAN E_01:53 sR-4h32 +0.36 39=20+19 |+4.51 03:18-07:00 6h25 05:30 158 17 -17 |
|   Moon:07d F_08:18 sR+1h53 -0.54 26=14+12d|-4.47 09:24-12:48 6h27 11:24  41 13 -03 |
|            E_14:45 sS-5h57 +0.33 43=24+19d|+4.02 16:06-19:18 5h50 17:48 141 14 -13 |
|            F_20:35 sS-0h07 -0.47 30=15+15d|-4.03 21:42-01:00 5h52 23:24  44 13 -01 |
|-----------|-------------------------------|----------------------------------------|
| THU_25_JAN E_02:27 sR-3h59 +0.37 38=18+20 |+4.48 03:54-07:24 6h20 06:06 155 17 -17 |
|   Moon:07d F_08:47 sR+2h21 -0.50 28=15+13d|-4.73 09:54-13:12 6h35 12:00  37 14 -02 |
|   1st_Qtr. E_15:22 sS-5h19 +0.33 43=23+20d|+4.13 16:48-20:00 6h02 18:30 141 15 -14 |
|            F_21:24 sS+0h43 -0.47 30=15+15 |-3.71 22:30-01:48 5h42 00:06  51 11 -02 |
|-----------|-------------------------------|----------------------------------------|
| FRI_26_JAN E_03:06 sR-3h21 +0.37 38=19+19 |+4.28 04:36-07:54 6h12 06:42 150 14 -14 |
|   Moon:08d F_09:18 sR+2h51 -0.47 30=15+15d|-4.94 10:30-13:36 6h46 12:36  34 16 -01 |
|            E_16:04 sS-4h37 +0.30 47=25+22d|+4.24 17:30-20:48 6h13 19:24 139 15 -13 |
|            F_22:17 sS+1h36 -0.44 32=16+16 |-3.31 23:30-02:36 5h33 00:48  59 11 -05 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_27_JAN E_03:50 sR-2h38 +0.33 43=21+22 |+3.93 05:18-08:30 6h04 07:24 145 13 -09 |
|   Moon:09d F_09:54 sR+3h26 -0.42 33=18+15d|-5.08 11:12-14:12 6h58 13:18  31 15 +01 |
|            E_16:52 sS-3h48 +0.31 45=24+21d|+4.33 18:30-21:42 6h26 20:24 138 14 -11 |
|            F_23:18 sS+2h38 -0.36 39=18+21 |-2.88 00:36-03:30 5h24 01:36  68 10 -09 |
|-----------|-------------------------------|----------------------------------------|
| SUN_28_JAN E_04:42 sR-1h47 +0.28 50=26+24 |+3.49 06:12-09:18 5h54 08:06 140 11 -03 |
|   Moon:10d F_10:36 sR+4h07 -0.39 36=19+17d|-5.09 12:00-15:06 7h12 14:06  29 16 +03 |
|            E_17:48 sS-2h51 +0.30 47=25+22d|+4.39 19:30-22:48 6h43 21:30 138 14 -10 |
|-----------|-------------------------------|----------------------------------------|
| MON_29_JAN F_00:31 sR-6h00 -0.28 50=22+28 |-2.54 01:54-04:36 5h13 02:30  76 11 -10 |
|   Moon:11d E_05:44 sR-0h47 +0.24 59=29+30 |+3.03 07:12-10:12 5h45 09:06 136 12 -01 |
|            F_11:29 sR+4h58 -0.35 40=21+19d|-5.02 12:54-16:06 7h24 15:06  29 17 +05 |
|            E_18:53 sS-1h45 +0.31 45=24+21d|+4.51 20:36-00:06 7h03 22:42 141 14 -09 |
|-----------|-------------------------------|----------------------------------------|
| TUE_30_JAN F_01:56 sR-4h36 -0.25 55=27+28 |-2.42 03:12-05:42 5h11 03:42  81 10 -05 |
|   Moon:12d E_07:07 sR+0h35 +0.22 64=34+30d|+2.73 08:42-11:24 5h28 10:12 133 08 +01 |
|            F_12:35 sS-8h03 -0.38 37=19+18d|-4.84 14:06-17:24 7h28 16:18  28 17 +04 |
|            E_20:03 sS-0h35 +0.34 41=21+20d|+4.66 21:48-01:24 7h11 23:54 146 14 -10 |
|-----------|-------------------------------|----------------------------------------|
| WED_31_JAN F_03:14 sR-3h19 -0.30 47=23+24 |-2.66 04:24-06:54 5h21 05:00  81 10 -03 |
|   Moon:14d E_08:35 sR+2h02 +0.23 61=30+31d|+2.81 10:12-12:48 5h13 11:30 133 08 -11 |
|  FULL_MOON F_13:48 sS-6h49 -0.42 33=17+16d|-4.67 15:18-18:48 7h23 17:36  25 13 -03 |
|            E_21:11 sS+0h34 +0.38 37=18+19 |+4.77 22:48-02:36 7h07 01:00 153 16 -14 |
|-----------|-------------------------------|----------------------------------------|

*********************** FEBRUARY 2018 ********************

 ----------- PACKO PREDICTION TABLE - PORT PHILLIP HEADS 2018 ----------------------- 
|-----------|-------------------------------|----------------------|-----------------|
| HEADING   | Left side: SLACK WATER INFO   | Right side: STREAM INFO +TIDE+Delay+Dif|
|-----------|-------------------------------|----------------------|-----------------|
| Date/Moon | Weekday_Date_Month. Age of the moon in days. Major phases of the moon. |
| SlkTime   | Slack Times (DLS corrected). Type: F_ = Flood slack, E_ = Ebb slack    |
| wrt.SUN   | Slack time RELATIVE to nearest sun_RISE(sR) or sun_SET(sS) +/- hrs&mins|
| Accln     | Rip current reversal rate in knots per 10mins. NB:sign is NOT flow dir.|
| SlkLngth  | Minutes between 0.7 knots & Slack. Total=BeforeSlk+AfterSlk, d=daySlack|
| MaxKn     | Max Predicted Rip Current (knots) from throughput. "+" =IN "-" =OUT    |
| >75%KnTime| Time interval (Time1 to Time2), when Rip Current exceeds 75% of MaxKn  |
| RunT      | RunTime of the tide stream FOLLOWING this slack. Time in hrs & minutes |
| TideT_H/L | Pt Lonsdale Hi/Lo Time & Height(cm). Last row times may wrap to new day|
| Dly       | Mins Delay to Rosebud Slack. Others: Portsea=30% Sorrento=45% Rye=70%  |
| Warning:- | Divers must ignore "Scuba Doctor's" delay times as they are NOT SAFE.  |
| Dif       | Minutes difference of packo slack times relative to Cardno (BoM) times.|
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| THU_01_FEB F_04:18 sR-2h16 -0.38 37=18+19 |-3.10 05:30-08:12 5h41 06:18  74 09 -03 |
|   Moon:15d E_09:59 sR+3h25 +0.23 60=31+29d|+3.16 11:24-14:06 5h02 12:48 138 12 -12 |
|            F_15:01 sS-5h35 -0.44 32=16+16d|-4.67 16:30-20:00 7h15 18:48  22 13 -10 |
|            E_22:16 sS+1h40 +0.38 37=19+18 |+5.12 23:48-03:36 6h54 02:00 161 17 -15 |
|-----------|-------------------------------|----------------------------------------|
| FRI_02_FEB F_05:10 sR-1h25 -0.45 31=15+16 |-3.61 06:24-09:24 5h59 07:30  63 12 -04 |
|   Moon:16d E_11:09 sR+4h34 +0.30 47=27+20d|+3.75 12:24-15:12 5h05 13:54 145 12 -09 |
|            F_16:14 sS-4h21 -0.40 35=18+17d|-4.73 17:36-21:12 7h01 19:48  19 14 -11 |
|            E_23:15 sS+2h40 +0.38 37=19+18 |+5.29 00:42-04:36 6h39 02:54 167 18 -15 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_03_FEB F_05:54 sR-0h42 -0.54 26=12+14 |-3.99 07:00-10:24 6h11 08:30  52 13 -06 |
|   Moon:17d E_12:05 sS-8h29 +0.39 36=20+16d|+4.33 13:18-16:06 5h18 14:54 152 12 -09 |
|            F_17:23 sS-3h11 -0.48 29=15+14d|-4.78 18:36-22:18 6h44 20:48  19 14 -08 |
|-----------|-------------------------------|----------------------------------------|
| SUN_04_FEB E_00:07 sR-6h30 +0.40 35=18+17 |+5.34 01:36-05:24 6h28 03:42 170 17 -15 |
|   Moon:18d F_06:35 sR-0h02 -0.61 23=11+12 |-4.38 07:42-11:06 6h19 09:24  41 12 -06 |
|            E_12:54 sS-7h39 +0.44 32=17+15d|+4.71 14:12-17:06 5h30 15:48 156 12 -11 |
|            F_18:24 sS-2h09 -0.56 25=13+12d|-4.81 19:30-23:06 6h30 21:36  22 13 -07 |
|-----------|-------------------------------|----------------------------------------|
| MON_05_FEB E_00:54 sR-5h45 +0.41 34=18+16 |+5.20 02:18-06:06 6h19 04:24 170 16 -16 |
|   Moon:19d F_07:13 sR+0h34 -0.67 21=10+11d|-4.59 08:18-11:54 6h27 10:12  33 12 -06 |
|            E_13:40 sS-6h52 +0.47 30=16+14d|+4.86 15:06-18:06 5h40 16:36 157 11 -12 |
|            F_19:20 sS-1h12 -0.61 23=12+11d|-4.68 20:24-23:54 6h17 22:24  28 12 -07 |
|-----------|-------------------------------|----------------------------------------|
| TUE_06_FEB E_01:37 sR-5h03 +0.41 34=18+16 |+5.04 03:00-06:42 6h13 05:06 167 15 -16 |
|   Moon:20d F_07:50 sR+1h10 -0.64 22=11+11d|-4.71 08:54-12:42 6h33 11:00  28 13 -05 |
|            E_14:23 sS-6h08 +0.48 29=15+14d|+4.81 15:54-19:06 5h49 17:30 155 11 -13 |
|            F_20:12 sS-0h19 -0.64 22=11+11d|-4.48 21:18-00:36 6h05 23:06  35 11 -08 |
|-----------|-------------------------------|----------------------------------------|
| WED_07_FEB E_02:17 sR-4h24 +0.40 35=18+17 |+4.81 03:42-07:18 6h09 05:48 162 15 -16 |
|   Moon:21d F_08:26 sR+1h45 -0.64 22=11+11d|-4.73 09:30-13:18 6h39 11:42  27 12 -04 |
|            E_15:05 sS-5h25 +0.48 29=15+14d|+4.67 16:36-20:00 5h57 18:18 150 11 -13 |
|            F_21:02 sS+0h32 -0.58 24=11+13 |-4.23 22:12-01:12 5h54 23:48  44 12 -09 |
|-----------|-------------------------------|----------------------------------------|
| THU_08_FEB E_02:56 sR-3h46 +0.38 37=19+18 |+4.47 04:18-07:48 6h05 06:24 156 14 -14 |
|   Moon:21d F_09:01 sR+2h19 -0.58 24=12+12d|-4.68 10:12-13:54 6h45 12:24  28 13 -02 |
|   3rd_Qtr. E_15:46 sS-4h43 +0.45 31=16+15d|+4.45 17:18-20:48 6h07 19:12 145 11 -12 |
|            F_21:53 sS+1h24 -0.48 29=14+15 |-3.93 23:06-02:00 5h41 00:24  52 10 -09 |
|-----------|-------------------------------|----------------------------------------|
| FRI_09_FEB E_03:34 sR-3h09 +0.35 40=20+20 |+4.14 05:00-08:12 6h01 07:00 148 13 -12 |
|   Moon:22d F_09:35 sR+2h52 -0.52 27=14+13d|-4.60 10:48-14:30 6h51 13:00  31 13 -01 |
|            E_16:26 sS-4h02 +0.42 33=16+17d|+4.26 17:54-21:30 6h19 20:00 139 11 -11 |
|            F_22:45 sS+2h17 -0.42 33=16+17 |-3.51 00:00-02:36 5h30 01:06  61 10 -10 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_10_FEB E_04:15 sR-2h29 +0.31 45=24+21 |+3.69 05:42-08:48 5h55 07:36 140 11 -09 |
|   Moon:23d F_10:10 sR+3h26 -0.44 32=17+15d|-4.42 11:30-15:06 6h58 13:42  35 13 +01 |
|            E_17:08 sS-3h19 +0.38 37=19+18d|+4.07 18:42-22:18 6h32 20:54 134 11 -10 |
|            F_23:40 sS+3h13 -0.35 40=18+22 |-3.12 01:00-03:24 5h19 01:48  70 11 -11 |
|-----------|-------------------------------|----------------------------------------|
| SUN_11_FEB E_04:59 sR-1h47 +0.27 52=27+25 |+3.10 06:36-09:30 5h47 08:12 133 09 -08 |
|   Moon:24d F_10:46 sR+4h00 -0.37 38=19+19d|-4.14 12:12-15:54 7h08 14:24  40 15 +01 |
|            E_17:54 sS-2h32 +0.33 42=22+20d|+3.92 19:30-23:06 6h49 21:48 130 09 -10 |
|-----------|-------------------------------|----------------------------------------|
| MON_12_FEB F_00:43 sR-6h04 -0.29 48=22+26 |-2.63 02:00-04:24 5h09 02:36  78 12 -10 |
|   Moon:25d E_05:52 sR-0h55 +0.22 65=31+34 |+2.52 07:42-10:18 5h40 09:00 126 07 -08 |
|            F_11:32 sR+4h45 -0.31 45=25+20d|-3.79 13:00-16:48 7h14 15:12  44 12 +05 |
|            E_18:46 sS-1h39 +0.30 47=23+24d|+3.84 20:30-00:06 7h07 22:42 129 12 -10 |
|-----------|-------------------------------|----------------------------------------|
| TUE_13_FEB F_01:53 sR-4h55 -0.26 54=27+27 |-2.34 03:00-05:30 5h11 03:36  84 10 -09 |
|   Moon:26d E_07:04 sR+0h16 +0.16 89=42+47d|+2.07 08:54-11:24 5h22 10:00 121 06 -12 |
|            F_12:26 sS-7h58 -0.29 49=27+22d|-3.52 14:00-17:54 7h21 16:18  47 12 +06 |
|            E_19:47 sS-0h37 +0.27 51=27+24d|+3.86 21:30-01:12 7h13 23:42 130 12 -09 |
|-----------|-------------------------------|----------------------------------------|
| WED_14_FEB F_03:00 sR-3h49 -0.28 50=25+25 |-2.36 04:00-06:42 5h33 04:54  86 11 -10 |
|   Moon:27d E_08:33 sR+1h44 +0.15 96=48+48d|+2.03 10:06-12:30 4h55 11:06 119 10 -19 |
|            F_13:28 sS-6h54 -0.27 51=26+25d|-3.37 15:12-19:00 7h21 17:30  47 12 +01 |
|            E_20:49 sS+0h27 +0.30 47=25+22 |+3.99 22:24-02:12 7h08 00:42 134 13 -10 |
|-----------|-------------------------------|----------------------------------------|
| THU_15_FEB F_03:57 sR-2h53 -0.33 42=21+21 |-2.60 05:00-07:54 5h50 06:12  82 09 -10 |
|   Moon:28d E_09:47 sR+2h57 +0.20 71=37+34d|+2.29 11:12-13:36 4h48 12:12 120 14 -20 |
|            F_14:35 sS-5h46 -0.30 47=23+24d|-3.39 16:12-20:06 7h11 18:30  44 11 -04 |
|            E_21:46 sS+1h25 +0.33 43=22+21 |+4.21 23:24-03:12 6h56 01:30 140 13 -11 |
|-----------|-------------------------------|----------------------------------------|
| FRI_16_FEB F_04:42 sR-2h09 -0.39 36=18+18 |-3.01 05:48-09:00 5h59 07:12  75 10 -09 |
|   Moon:00d E_10:41 sR+3h50 +0.25 56=29+27d|+2.75 12:00-14:36 4h58 13:12 125 13 -18 |
|   NEW_MOON F_15:39 sS-4h41 -0.31 45=22+23d|-3.49 17:06-21:12 6h58 19:24  41 12 -07 |
|            E_22:37 sS+2h17 +0.34 41=21+20 |+4.43 00:06-03:54 6h42 02:12 146 15 -10 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_17_FEB F_05:19 sR-1h33 -0.45 31=15+16 |-3.40 06:24-09:48 6h05 08:00  66 11 -08 |
|   Moon:01d E_11:24 sR+4h32 +0.30 47=25+22d|+3.26 12:42-15:24 5h12 14:00 132 12 -17 |
|            F_16:36 sS-3h43 -0.35 40=20+20d|-3.73 17:54-21:54 6h45 20:12  38 14 -07 |
|            E_23:21 sS+3h02 +0.36 39=21+18 |+4.63 00:48-04:30 6h30 02:48 152 15 -09 |
|-----------|-------------------------------|----------------------------------------|
| SUN_18_FEB F_05:51 sR-1h02 -0.48 29=14+15 |-3.71 07:00-10:24 6h10 08:42  58 13 -07 |
|   Moon:02d E_12:01 sS-8h16 +0.33 43=23+20d|+3.64 13:18-16:12 5h26 14:48 138 13 -16 |
|            F_17:27 sS-2h50 -0.41 34=18+16d|-3.94 18:36-22:24 6h32 20:48  37 13 -06 |
|            E_23:59 sS+3h42 +0.36 39=20+19 |+4.69 01:30-05:00 6h22 03:24 156 16 -11 |
|-----------|-------------------------------|----------------------------------------|
| MON_19_FEB F_06:21 sR-0h33 -0.52 27=14+13 |-3.96 07:24-11:00 6h14 09:18  49 12 -05 |
|   Moon:03d E_12:35 sS-7h41 +0.35 40=21+19d|+4.06 13:54-17:00 5h37 15:30 144 14 -16 |
|            F_18:12 sS-2h04 -0.45 31=16+15d|-4.13 19:18-23:00 6h21 21:24  37 14 -06 |
|-----------|-------------------------------|----------------------------------------|
| TUE_20_FEB E_00:33 sR-6h23 +0.34 41=21+20 |+4.60 02:00-05:30 6h16 04:00 158 18 -14 |
|   Moon:04d F_06:49 sR-0h07 -0.54 26=14+12 |-4.23 07:54-11:30 6h21 09:54  42 12 -05 |
|            E_13:10 sS-7h05 +0.36 39=22+17d|+4.31 14:30-17:42 5h47 16:12 149 14 -15 |
|            F_18:57 sS-1h18 -0.50 28=14+14d|-4.22 20:06-23:30 6h09 22:00  39 13 -04 |
|-----------|-------------------------------|----------------------------------------|
| WED_21_FEB E_01:06 sR-5h51 +0.33 42=22+20 |+4.53 02:30-06:00 6h11 04:36 159 18 -16 |
|   Moon:05d F_07:17 sR+0h20 -0.56 25=13+12d|-4.47 08:18-12:00 6h28 10:30  36 13 -04 |
|            E_13:45 sS-6h29 +0.37 38=21+17d|+4.51 15:06-18:24 5h57 16:54 151 15 -14 |
|            F_19:42 sS-0h32 -0.52 27=14+13d|-4.18 20:48-00:12 5h57 22:36  41 12 -02 |
|-----------|-------------------------------|----------------------------------------|
| THU_22_FEB E_01:39 sR-5h19 +0.35 40=20+20 |+4.42 03:06-06:36 6h07 05:06 157 17 -19 |
|   Moon:06d F_07:46 sR+0h48 -0.54 26=13+13d|-4.71 08:54-12:18 6h36 11:00  31 14 -03 |
|            E_14:22 sS-5h50 +0.36 39=21+18d|+4.56 15:42-19:06 6h05 17:36 152 16 -12 |
|            F_20:27 sS+0h15 -0.50 28=14+14 |-4.06 21:36-00:54 5h47 23:12  46 12 -02 |
|-----------|-------------------------------|----------------------------------------|
| FRI_23_FEB E_02:14 sR-4h45 +0.34 41=20+21 |+4.24 03:36-07:06 6h02 05:42 154 16 -19 |
|   Moon:07d F_08:16 sR+1h17 -0.54 26=13+13d|-4.91 09:24-12:42 6h44 11:36  27 15 -03 |
|   1st_Qtr. E_15:00 sS-5h11 +0.34 41=22+19d|+4.66 16:24-19:48 6h15 18:18 151 17 -12 |
|            F_21:15 sS+1h04 -0.48 29=15+14 |-3.83 22:30-01:36 5h37 23:54  52 10 -02 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_24_FEB E_02:52 sR-4h08 +0.33 42=20+22 |+4.09 04:18-07:30 5h57 06:18 150 16 -17 |
|   Moon:08d F_08:49 sR+1h49 -0.47 30=16+14d|-5.06 10:00-13:12 6h52 12:18  25 15 -02 |
|            E_15:41 sS-4h29 +0.33 42=22+20d|+4.66 17:06-20:36 6h24 19:06 148 17 -12 |
|            F_22:05 sS+1h55 -0.45 31=15+16 |-3.52 23:30-02:24 5h30 00:36  59 09 -04 |
|-----------|-------------------------------|----------------------------------------|
| SUN_25_FEB E_03:35 sR-3h26 +0.33 42=21+21 |+3.82 05:00-08:12 5h52 07:00 145 13 -12 |
|   Moon:09d F_09:27 sR+2h26 -0.42 33=19+14d|-5.13 10:42-14:00 7h01 12:54  25 15 +01 |
|            E_16:28 sS-3h40 +0.31 45=25+20d|+4.61 18:00-21:24 6h33 20:00 144 16 -10 |
|            F_23:01 sS+2h53 -0.38 37=17+20 |-3.12 00:30-03:12 5h24 01:24  66 10 -06 |
|-----------|-------------------------------|----------------------------------------|
| MON_26_FEB E_04:25 sR-2h37 +0.29 48=25+23 |+3.44 05:48-09:00 5h45 07:42 140 10 -06 |
|   Moon:10d F_10:10 sR+3h08 -0.40 35=18+17d|-4.98 11:30-14:48 7h11 13:42  27 16 +02 |
|            E_17:21 sS-2h46 +0.30 46=25+21d|+4.49 19:00-22:24 6h46 21:06 140 15 -10 |
|-----------|-------------------------------|----------------------------------------|
| TUE_27_FEB F_00:07 sR-6h56 -0.30 47=21+26 |-2.73 01:30-04:12 5h18 02:12  73 10 -07 |
|   Moon:11d E_05:25 sR-1h38 +0.26 54=27+27 |+3.04 06:54-09:54 5h42 08:42 135 10 -01 |
|            F_11:07 sR+4h04 -0.37 38=20+18d|-4.76 12:36-15:48 7h19 14:42  31 16 +05 |
|            E_18:26 sS-1h39 +0.30 46=25+21d|+4.32 20:12-23:42 6h58 22:18 138 13 -08 |
|-----------|-------------------------------|----------------------------------------|
| WED_28_FEB F_01:24 sR-5h40 -0.27 51=25+26 |-2.59 02:42-05:18 5h19 03:18  77 10 -05 |
|   Moon:12d E_06:43 sR-0h21 +0.22 63=33+30 |+2.80 08:18-11:00 5h36 09:54 131 09 -02 |
|            F_12:19 sS-7h45 -0.36 39=21+18d|-4.45 13:48-17:12 7h20 15:54  35 15 +04 |
|            E_19:39 sS-0h25 +0.33 43=23+20d|+4.31 21:24-01:00 7h01 23:30 140 12 -10 |
|-----------|-------------------------------|----------------------------------------|

*********************** MARCH 2018 ********************

 ----------- PACKO PREDICTION TABLE - PORT PHILLIP HEADS 2018 ----------------------- 
|-----------|-------------------------------|----------------------|-----------------|
| HEADING   | Left side: SLACK WATER INFO   | Right side: STREAM INFO +TIDE+Delay+Dif|
|-----------|-------------------------------|----------------------|-----------------|
| Date/Moon | Weekday_Date_Month. Age of the moon in days. Major phases of the moon. |
| SlkTime   | Slack Times (DLS corrected). Type: F_ = Flood slack, E_ = Ebb slack    |
| wrt.SUN   | Slack time RELATIVE to nearest sun_RISE(sR) or sun_SET(sS) +/- hrs&mins|
| Accln     | Rip current reversal rate in knots per 10mins. NB:sign is NOT flow dir.|
| SlkLngth  | Minutes between 0.7 knots & Slack. Total=BeforeSlk+AfterSlk, d=daySlack|
| MaxKn     | Max Predicted Rip Current (knots) from throughput. "+" =IN "-" =OUT    |
| >75%KnTime| Time interval (Time1 to Time2), when Rip Current exceeds 75% of MaxKn  |
| RunT      | RunTime of the tide stream FOLLOWING this slack. Time in hrs & minutes |
| TideT_H/L | Pt Lonsdale Hi/Lo Time & Height(cm). Last row times may wrap to new day|
| Dly       | Mins Delay to Rosebud Slack. Others: Portsea=30% Sorrento=45% Rye=70%  |
| Warning:- | Divers must ignore "Scuba Doctor's" delay times as they are NOT SAFE.  |
| Dif       | Minutes difference of packo slack times relative to Cardno (BoM) times.|
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| THU_01_MAR F_02:40 sR-4h25 -0.30 47=24+23 |-2.73 03:48-06:30 5h34 04:42  77 09 -04 |
|   Moon:13d E_08:14 sR+1h09 +0.23 61=31+30d|+2.88 10:00-12:36 5h24 11:18 131 08 -12 |
|            F_13:38 sS-6h25 -0.39 36=18+18d|-4.16 15:06-18:42 7h15 17:18  36 12 -05 |
|            E_20:53 sS+0h50 +0.33 42=21+21 |+4.38 22:30-02:12 6h51 00:36 146 14 -13 |
|-----------|-------------------------------|----------------------------------------|
| FRI_02_MAR F_03:44 sR-3h22 -0.38 37=18+19 |-3.20 05:00-07:54 5h56 06:00  69 11 -06 |
|   Moon:14d E_09:40 sR+2h34 +0.25 57=30+27d|+3.33 11:06-14:00 5h21 12:36 137 16 -15 |
|  FULL_MOON F_15:01 sS-5h00 -0.37 38=19+19d|-4.15 16:24-20:06 7h03 18:36  34 13 -10 |
|            E_22:04 sS+2h03 +0.34 41=22+19 |+4.67 23:36-03:12 6h34 01:36 153 16 -13 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_03_MAR F_04:38 sR-2h29 -0.47 30=15+15 |-3.68 05:48-09:06 6h14 07:12  57 11 -05 |
|   Moon:15d E_10:52 sR+3h45 +0.31 45=26+19d|+4.03 12:12-15:00 5h28 13:42 146 12 -09 |
|            F_16:20 sS-3h40 -0.41 34=18+16d|-4.31 17:36-21:18 6h46 19:42  32 14 -08 |
|            E_23:06 sS+3h06 +0.37 38=21+17 |+4.82 00:30-04:06 6h17 02:30 159 15 -11 |
|-----------|-------------------------------|----------------------------------------|
| SUN_04_MAR F_05:23 sR-1h45 -0.54 26=13+13 |-4.14 06:30-10:00 6h23 08:12  45 12 -05 |
|   Moon:16d E_11:46 sR+4h38 +0.41 34=19+15d|+4.58 13:00-16:06 5h38 14:42 155 12 -10 |
|            F_17:24 sS-2h34 -0.54 26=13+13d|-4.42 18:36-22:12 6h34 20:36  32 13 -09 |
|            E_23:58 sS+4h00 +0.39 36=20+16 |+4.91 01:24-04:54 6h05 03:18 163 15 -11 |
|-----------|-------------------------------|----------------------------------------|
| MON_05_MAR F_06:03 sR-1h06 -0.61 23=11+12 |-4.44 07:12-10:42 6h29 09:06  35 13 -06 |
|   Moon:17d E_12:32 sS-7h25 +0.45 31=17+14d|+4.95 13:54-17:06 5h48 15:36 160 12 -12 |
|            F_18:20 sS-1h37 -0.58 24=12+12d|-4.48 19:24-22:54 6h23 21:24  34 12 -09 |
|-----------|-------------------------------|----------------------------------------|
| TUE_06_MAR E_00:43 sR-6h27 +0.41 34=18+16 |+4.85 02:06-05:30 5h58 04:00 164 15 -12 |
|   Moon:18d F_06:41 sR-0h29 -0.64 22=11+11 |-4.66 07:48-11:24 6h33 09:48  28 12 -05 |
|            E_13:14 sS-6h41 +0.48 29=16+13d|+5.07 14:36-18:00 5h56 16:30 163 12 -13 |
|            F_19:10 sS-0h45 -0.64 22=11+11d|-4.46 20:18-23:36 6h13 22:06  37 11 -10 |
|-----------|-------------------------------|----------------------------------------|
| WED_07_MAR E_01:23 sR-5h48 +0.41 34=18+16 |+4.73 02:42-06:06 5h54 04:36 162 14 -13 |
|   Moon:19d F_07:17 sR+0h06 -0.64 22=11+11d|-4.76 08:24-12:06 6h36 10:36  24 12 -04 |
|            E_13:53 sS-6h01 +0.48 29=15+14d|+5.03 15:18-18:54 6h04 17:12 161 12 -14 |
|            F_19:57 sS+0h03 -0.61 23=11+12 |-4.45 21:06-00:12 6h04 22:42  42 12 -10 |
|-----------|-------------------------------|----------------------------------------|
| THU_08_MAR E_02:01 sR-5h11 +0.40 35=19+16 |+4.56 03:18-06:36 5h51 05:12 158 13 -13 |
|   Moon:20d F_07:52 sR+0h40 -0.61 23=12+11d|-4.72 08:54-12:48 6h39 11:12  24 12 -02 |
|            E_14:31 sS-5h21 +0.50 28=15+13d|+4.90 15:54-19:36 6h12 17:54 158 12 -13 |
|            F_20:43 sS+0h51 -0.56 25=12+13 |-4.30 21:54-00:54 5h54 23:24  48 11 -08 |
|-----------|-------------------------------|----------------------------------------|
| FRI_09_MAR E_02:37 sR-4h36 +0.37 38=20+18 |+4.35 04:00-07:06 5h48 05:48 152 13 -12 |
|   Moon:21d F_08:25 sR+1h12 -0.56 25=13+12d|-4.70 09:36-13:18 6h43 11:48  26 13 -01 |
|   3rd_Qtr. E_15:08 sS-4h43 +0.48 29=16+13d|+4.71 16:30-20:12 6h19 18:36 152 11 -12 |
|            F_21:27 sS+1h36 -0.50 28=13+15 |-4.11 22:42-01:30 5h45 00:00  54 11 -06 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_10_MAR E_03:12 sR-4h02 +0.35 40=21+19 |+4.03 04:36-07:42 5h46 06:18 146 12 -10 |
|   Moon:22d F_08:58 sR+1h44 -0.48 29=16+13d|-4.55 10:12-13:54 6h47 12:24  30 13 +01 |
|            E_15:45 sS-4h04 +0.45 31=17+14d|+4.53 17:06-20:48 6h26 19:18 145 11 -09 |
|            F_22:11 sS+2h22 -0.42 33=16+17 |-3.81 23:30-02:06 5h37 00:36  61 11 -05 |
|-----------|-------------------------------|----------------------------------------|
| SUN_11_MAR E_03:48 sR-3h27 +0.33 43=23+20 |+3.56 05:12-08:18 5h42 06:54 139 10 -09 |
|   Moon:23d F_09:30 sR+2h15 -0.42 33=17+16d|-4.34 10:48-14:30 6h53 13:00  35 14 +00 |
|            E_16:23 sS-3h25 +0.41 34=18+16d|+4.28 17:48-21:24 6h35 20:00 139 10 -07 |
|            F_22:58 sS+3h10 -0.37 38=18+20 |-3.36 00:18-02:48 5h29 01:18  68 10 -03 |
|-----------|-------------------------------|----------------------------------------|
| MON_12_MAR E_04:27 sR-2h49 +0.30 47=24+23 |+3.07 05:54-08:54 5h39 07:36 132 09 -07 |
|   Moon:24d F_10:06 sR+2h50 -0.38 37=19+18d|-4.02 11:24-15:06 6h58 13:36  41 14 +02 |
|            E_17:04 sS-2h42 +0.37 38=20+18d|+4.08 18:42-22:06 6h46 20:48 133 11 -06 |
|            F_23:50 sS+4h04 -0.30 47=24+23 |-2.88 01:12-03:42 5h22 01:54  75 08 -03 |
|-----------|-------------------------------|----------------------------------------|
| TUE_13_MAR E_05:12 sR-2h05 +0.25 55=27+28 |+2.50 06:42-09:42 5h37 08:18 126 08 -07 |
|   Moon:25d F_10:49 sR+3h32 -0.32 44=24+20d|-3.69 12:12-15:54 7h02 14:24  47 14 +04 |
|            E_17:51 sS-1h54 +0.30 46=23+23d|+3.83 19:36-23:06 6h58 21:42 129 11 -07 |
|-----------|-------------------------------|----------------------------------------|
| WED_14_MAR F_00:49 sR-6h29 -0.26 54=26+28 |-2.52 02:12-04:36 5h22 02:48  81 08 -06 |
|   Moon:26d E_06:11 sR-1h07 +0.20 71=33+38 |+2.06 07:54-10:36 5h32 09:18 120 05 -10 |
|            F_11:43 sR+4h25 -0.26 54=29+25d|-3.24 13:12-16:54 7h08 15:18  53 14 +05 |
|            E_18:51 sS-0h52 +0.25 56=29+27d|+3.66 20:42-00:06 7h03 22:48 127 10 -05 |
|-----------|-------------------------------|----------------------------------------|
| THU_15_MAR F_01:54 sR-5h25 -0.25 57=28+29 |-2.40 03:12-05:54 5h37 04:00  84 10 -09 |
|   Moon:27d E_07:31 sR+0h12 +0.15 93=42+51d|+1.93 09:18-11:48 5h22 10:24 118 07 -21 |
|            F_12:53 sS-6h49 -0.24 58=32+26d|-3.01 14:30-18:00 7h08 16:24  57 13 +04 |
|            E_20:01 sS+0h19 +0.24 58=30+28 |+3.64 21:48-01:12 6h56 23:48 129 13 -06 |
|-----------|-------------------------------|----------------------------------------|
| FRI_16_MAR F_02:57 sR-4h23 -0.27 51=26+25 |-2.59 04:06-07:00 5h58 05:24  81 11 -10 |
|   Moon:28d E_08:55 sR+1h35 +0.17 81=42+39d|+2.22 10:24-13:00 5h16 11:36 119 12 -24 |
|            F_14:11 sS-5h29 -0.26 54=28+26d|-2.96 15:42-19:18 6h58 17:48  57 10 -01 |
|            E_21:09 sS+1h29 +0.27 51=26+25 |+3.76 22:48-02:18 6h38 00:48 134 14 -09 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_17_MAR F_03:47 sR-3h34 -0.33 42=21+21 |-2.97 05:00-08:18 6h10 06:36  74 13 -11 |
|   Moon:00d E_09:57 sR+2h36 +0.23 60=32+28d|+2.78 11:18-14:18 5h27 12:48 126 11 -20 |
|   NEW_MOON F_15:24 sS-4h15 -0.30 47=24+23d|-3.10 16:42-20:36 6h44 18:54  54 12 -05 |
|            E_22:08 sS+2h29 +0.30 46=24+22 |+3.97 23:36-03:06 6h21 01:30 140 15 -09 |
|-----------|-------------------------------|----------------------------------------|
| SUN_18_MAR F_04:29 sR-2h53 -0.40 35=18+17 |-3.36 05:36-09:12 6h13 07:30  63 12 -09 |
|   Moon:01d E_10:42 sR+3h20 +0.29 48=24+24d|+3.44 12:06-15:12 5h43 13:42 135 14 -20 |
|            F_16:25 sS-3h12 -0.36 39=20+19d|-3.35 17:36-21:30 6h33 19:42  51 13 -07 |
|            E_22:58 sS+3h21 +0.33 43=23+20 |+4.15 00:24-03:48 6h06 02:18 147 15 -08 |
|-----------|-------------------------------|----------------------------------------|
| MON_19_MAR F_05:04 sR-2h19 -0.47 30=15+15 |-3.78 06:12-09:54 6h19 08:06  53 12 -08 |
|   Moon:02d E_11:23 sR+4h00 +0.33 42=22+20d|+4.03 12:42-16:00 5h54 14:30 145 14 -17 |
|            F_17:17 sS-2h19 -0.42 33=17+16d|-3.66 18:24-22:06 6h23 20:24  49 13 -07 |
|            E_23:40 sS+4h04 +0.33 43=23+20 |+4.23 01:06-04:24 5h56 02:54 152 15 -09 |
|-----------|-------------------------------|----------------------------------------|
| TUE_20_MAR F_05:36 sR-1h48 -0.50 28=14+14 |-4.18 06:42-10:24 6h25 08:48  43 13 -07 |
|   Moon:03d E_12:01 sS-7h33 +0.35 40=22+18d|+4.46 13:18-16:42 6h03 15:18 154 16 -16 |
|            F_18:04 sS-1h30 -0.50 28=15+13d|-3.95 19:06-22:42 6h14 21:06  47 12 -07 |
|-----------|-------------------------------|----------------------------------------|
| WED_21_MAR E_00:18 sR-7h07 +0.33 43=23+20 |+4.25 01:36-05:00 5h49 03:30 155 16 -11 |
|   Moon:04d F_06:07 sR-1h18 -0.54 26=13+13 |-4.51 07:12-10:48 6h31 09:24  35 14 -06 |
|            E_12:38 sS-6h55 +0.37 38=20+18d|+4.86 13:54-17:30 6h11 16:00 161 18 -15 |
|            F_18:49 sS-0h44 -0.52 27=14+13d|-4.16 20:00-23:18 6h04 21:42  47 11 -06 |
|-----------|-------------------------------|----------------------------------------|
| THU_22_MAR E_00:53 sR-6h33 +0.32 44=23+21 |+4.11 02:12-05:36 5h46 04:06 156 18 -15 |
|   Moon:05d F_06:39 sR-0h47 -0.54 26=13+13 |-4.77 07:48-11:12 6h37 10:00  28 14 -05 |
|            E_13:16 sS-6h15 +0.38 37=19+18d|+5.01 14:36-18:12 6h18 16:42 164 18 -14 |
|            F_19:34 sS+0h03 -0.52 27=14+13 |-4.26 20:48-23:54 5h55 22:18  49 11 -05 |
|-----------|-------------------------------|----------------------------------------|
| FRI_23_MAR E_01:29 sR-5h58 +0.33 43=22+21 |+4.08 02:48-06:12 5h43 04:42 155 18 -16 |
|   Moon:06d F_07:12 sR-0h15 -0.52 27=13+14 |-4.92 08:18-11:48 6h44 10:36  24 15 -04 |
|            E_13:56 sS-5h33 +0.36 39=21+18d|+5.13 15:18-18:54 6h23 17:24 165 19 -12 |
|            F_20:19 sS+0h50 -0.52 27=13+14 |-4.22 21:42-00:42 5h48 23:00  52 11 -04 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_24_MAR E_02:07 sR-5h21 +0.32 44=23+21 |+3.97 03:24-06:42 5h40 05:18 153 16 -16 |
|   Moon:07d F_07:47 sR+0h19 -0.50 28=14+14d|-4.96 08:54-12:18 6h50 11:18  22 15 -03 |
|            E_14:37 sS-4h51 +0.37 38=20+18d|+5.05 16:00-19:36 6h28 18:06 162 18 -11 |
|            F_21:05 sS+1h37 -0.50 28=13+15 |-4.01 22:30-01:24 5h40 23:42  56 12 -04 |
|-----------|-------------------------------|----------------------------------------|
| SUN_25_MAR E_02:45 sR-4h44 +0.32 44=21+23 |+3.73 04:06-07:24 5h40 05:54 150 16 -16 |
|   Moon:07d F_08:25 sR+0h56 -0.47 30=16+14d|-4.98 09:36-13:00 6h55 11:54  23 15 -02 |
|   1st_Qtr. E_15:20 sS-4h06 +0.35 40=21+19d|+4.93 16:42-20:18 6h34 18:48 157 17 -11 |
|            F_21:54 sS+2h28 -0.44 32=15+17 |-3.76 23:24-02:06 5h35 00:24  61 11 -04 |
|-----------|-------------------------------|----------------------------------------|
| MON_26_MAR E_03:29 sR-4h01 +0.30 47=24+23 |+3.52 04:48-08:00 5h38 06:42 145 13 -12 |
|   Moon:08d F_09:07 sR+1h37 -0.44 32=16+16d|-4.89 10:24-13:48 7h00 12:42  26 16 -01 |
|            E_16:07 sS-3h18 +0.34 41=23+18d|+4.70 17:36-21:12 6h39 19:42 150 15 -09 |
|            F_22:46 sS+3h21 -0.39 36=17+19 |-3.43 00:12-02:54 5h33 01:06  66 11 -05 |
|-----------|-------------------------------|----------------------------------------|
| TUE_27_MAR E_04:19 sR-3h12 +0.29 49=25+24 |+3.23 05:36-08:48 5h38 07:30 140 11 -08 |
|   Moon:09d F_09:57 sR+2h26 -0.37 38=20+18d|-4.68 11:18-14:36 7h02 13:30  32 16 +00 |
|            E_16:59 sS-2h24 +0.33 43=23+20d|+4.45 18:36-22:06 6h45 20:42 144 13 -09 |
|            F_23:44 sS+4h21 -0.35 40=19+21 |-3.14 01:06-03:48 5h37 02:00  71 12 -06 |
|-----------|-------------------------------|----------------------------------------|
| WED_28_MAR E_05:21 sR-2h11 +0.26 54=30+24 |+3.04 06:48-09:42 5h40 08:30 134 07 -04 |
|   Moon:10d F_11:01 sR+3h29 -0.37 38=21+17d|-4.28 12:24-15:48 7h00 14:24  40 14 +02 |
|            E_18:01 sS-1h21 +0.31 45=24+21d|+4.22 19:48-23:12 6h48 21:54 140 12 -09 |
|-----------|-------------------------------|----------------------------------------|
| THU_29_MAR F_00:49 sR-6h44 -0.32 44=21+23 |-2.99 02:06-04:54 5h47 03:06  73 11 -07 |
|   Moon:11d E_06:36 sR-0h57 +0.23 60=31+29 |+2.92 08:18-11:00 5h41 09:48 131 09 -08 |
|            F_12:17 sS-7h03 -0.36 39=19+20d|-3.90 13:48-17:06 6h57 15:36  48 14 -02 |
|            E_19:14 sS-0h06 +0.29 48=25+23d|+4.04 21:06-00:30 6h44 23:06 140 12 -11 |
|-----------|-------------------------------|----------------------------------------|
| FRI_30_MAR F_01:58 sR-5h36 -0.33 43=22+21 |-3.11 03:12-06:12 6h04 04:30  71 11 -07 |
|   Moon:12d E_08:02 sR+0h28 +0.24 59=28+31d|+3.11 09:42-12:42 5h42 11:18 133 12 -16 |
|            F_13:44 sS-5h35 -0.34 41=20+21d|-3.62 15:06-18:36 6h49 17:00  52 13 -08 |
|            E_20:33 sS+1h14 +0.30 47=24+23 |+4.01 22:12-01:42 6h30 00:12 143 13 -14 |
|-----------|-------------------------------|----------------------------------------|
|  Date/Moon SlkTime wrt.SUN Accln SlkLngth  MaxKn >75%KnTimes RunT TideT_H/L Dly Dif|
|-----------|-------------------------------|----------------------------------------|
| SAT_31_MAR F_03:03 sR-4h31 -0.38 37=19+18 |-3.52 04:18-07:30 6h22 05:48  62 11 -06 |
|   Moon:14d E_09:25 sR+1h51 +0.27 51=27+24d|+3.72 10:54-13:54 5h47 12:30 141 15 -13 |
|  FULL_MOON F_15:12 sS-4h05 -0.37 38=20+18d|-3.66 16:30-20:00 6h37 18:24  51 13 -09 |
|            E_21:49 sS+2h32 +0.30 46=24+22 |+4.22 23:18-02:36 6h09 01:06 148 16 -11 |
|-----------|-------------------------------|----------------------------------------|

**************** MONTH-BY-MONTH IMAGE FORMAT *******************************

Links to the "monthly image" format jpeg files are given below:-

January link: January 2018 predictions

February link: February 2018 predictions

March link: March 2018 predictions

Note my claim that the above predictions should be accurate to within a handful of minutes is only on the proviso that there is little or no additional "weather current" component in or out through the Heads at that time. Divers can check if this condition is met by seeing if the near real-time "Point Richards Tidal surge plot" is very flat around and during the lead-up to each slack water event by using this link:

Direct VRCA tide plot link

a) Note that the "surge plot" doesn't have to be zero, but just "flat" around slack water.

b) Note that the Rip slack water times can be roughly estimated by looking just a little (10 mins) before the max or min times of the red Pt Richards predicted tide curve in the panel above the surge plot.

c) Note that you will need to reload the image from this link roughly every 5 minutes to keep it up to date.

d) If the surge plot is rising, Flood slacks will be delayed and Ebb slacks will arrive earlier than predicted.

e) If the surge plot is falling, Ebb slacks will be delayed and Flood slacks will arrive earlier than predicted.

f) The "full monty" on "weather currents" and "weather corrections" can be found at:-

Packo's Weather Corrections Post (It is a bit complicated, so to avoid headaches take in small doses!)

cheers,
packo
Last Edit: 1 month 6 days ago by packo. Reason: 2018 update#1

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