Ft. Pickens Jettie (dive on a slack tide?)

[LollyO]

We are thinking about a shore dive at Ft. Pickens' Jetties (Beach Dive) at Pensacola Beach

A website warns us to because of strong currents that accompany each tidal change, it is extremely important to dive on a slack tide.


Pensacola Bay entrance, midchannel, Florida Current
Tide/Current Predictor

2009-08-29 06:24 CDT Sunrise
2009-08-29 07:48 CDT -0.00 knots Slack, Ebb Begins
2009-08-29 12:13 CDT -2.35 knots Max Ebb
2009-08-29 15:35 CDT Moonrise
2009-08-29 18:52 CDT 0.00 knots Slack, Flood Begins
2009-08-29 19:15 CDT Sunset

Given the above info.....when is the slack tide?

Thanks,
Lolly

 

[mike_s]

you want to dive it at "high slack tide". at high tide, it's just pulled in fresh water from the gulf and current is a minimal


I use www.saltwatertides.com . It's easier to read.

for the 28th it says.

Tides for Pensacola Bay Entrance starting with August 28, 2009.

Day        High      Tide  Height   Sunrise    Moon  Time      % Moon
           /Low      Time    Feet    Sunset                    Visible

F   28     High   3:50 AM     1.4   6:24 AM     Set 12:01 AM      54
    28      Low   4:58 PM     0.1   7:17 PM    Rise  2:47 PM

Sa  29     High   5:06 AM     1.4   6:25 AM     Set 12:52 AM      63
    29      Low   5:53 PM     0.1   7:15 PM    Rise  3:36 PM

Su  30     High   6:17 AM     1.4   6:25 AM     Set  1:46 AM      72
    30      Low   6:34 PM     0.1   7:14 PM    Rise  4:19 PM

according to the above chart....

for the 29th, "high slack tide" is at 5:06am. (you gonna dive that early?)

 

[LollyO]

Wow, a few miles makes a huge difference....I chose mid channel because it looks like its closer to the Jetties, but you may be right that the Entrance is better...but ugh...there are a couple of different spots referencing the Entrance. Also mid channel obviously uses different terminology because its in the middle??? 5:AM is not too early...but it is too dark for me.

Entrance, Pensacola Bay, Florida 30.3333° N, 87.3167° W
2009-08-29 05:05 CDT 1.38 feet High Tide
2009-08-29 06:24 CDT Sunrise
2009-08-29 15:35 CDT Moonrise
2009-08-29 17:52 CDT 0.06 feet Low Tide
2009-08-29 19:15 CDT Sunset


Pensacola Bay Entrance, Pensacola Bay, Florida 30.3267° N, 87.3117° W
[2009-08-29 05:27 CDT 1.39 feet High Tide2009-08-29 06:24 CDT Sunrise
2009-08-29 15:35 CDT Moonrise
2009-08-29 18:00 CDT 0.15 feet Low Tide
2009-08-29 19:15 CDT Sunset


Fishing Bend, Santa Rosa Sound, Florida 30.3333° N, 87.1333° W
2009-08-29 06:23 CDT Sunrise
2009-08-29 07:09 CDT 1.90 feet High Tide2009-08-29 15:34 CDT Moonrise
2009-08-29 19:14 CDT Sunset
2009-08-29 19:17 CDT 0.08 feet Low Tide

 

[mike_s]

Yep... a few miles makes a difference. blame it on the Moon.


Destin for example is about an hour later that day

Tides for East Pass (Destin) starting with August 28, 2009.

Day        High      Tide  Height   Sunrise    Moon  Time      % Moon
           /Low      Time    Feet    Sunset                    Visible

F   28     High   4:39 AM     0.8   6:21 AM    Rise  2:44 PM      54
    28      Low   4:58 PM     0.0   7:13 PM

Sa  29     High   5:55 AM     0.8   6:21 AM     Set 12:49 AM      63
    29      Low   5:53 PM     0.0   7:12 PM    Rise  3:33 PM

Su  30     High   7:06 AM     0.8   6:22 AM     Set  1:42 AM      72
    30      Low   6:34 PM     0.0   7:11 PM    Rise  4:16 PM

Panama City St Andrews, yet again different

Tides for St. Andrew Bay Channel entrance starting with August 28, 2009.

Day        High      Tide  Height   Sunrise    Moon  Time      % Moon
           /Low      Time    Feet    Sunset                    Visible

F   28     High   3:34 AM     1.7   6:18 AM    Rise  2:40 PM      54
    28      Low   3:42 PM     0.1   7:10 PM

Sa  29     High   4:50 AM     1.7   6:18 AM     Set 12:46 AM      63
    29      Low   4:37 PM     0.1   7:09 PM    Rise  3:29 PM

Su  30     High   6:01 AM     1.7   6:19 AM     Set  1:40 AM      72
    30      Low   5:18 PM     0.1   7:08 PM    Rise  4:12 PM

 

[LollyO]

you want to dive it at "high slack tide". at high tide, it's just pulled in fresh water from the gulf and current is a minimal

I read somewhere that not all high tides are high slack tides.
is that true....if so why?

thanks

 

[Nemrod]

I read somewhere that not all high tides are high slack tides.
is that true....if so why?

thanks

Between an incoming tide and an out going tide there will be a point where the water is slack. The duration and nature of that period will vary depending upon the locale, the geography, the lunar cycle and all of that stuff.

www.saltwatertides.com

N

 

[gcbryan]

A far as I know slack actually refers to current. Tides go up and down. Currents go in and out. When a current stops moving when changing direction...that's slack.

You you have a slack before ebb at 7:48am and a slack before flood at 6:52pm. In general ebb will be going out and flood will be coming in but it depends on the local topography in case there are local inlets or other narrow restrictions.

The best advice will probably be available in one of the local (Florida) sections of this board as it's hard to beat local knowledge!

Without knowing the site it's hard to say if it can be done on either slack or only on a slack before flood for instance. In some cases when strong current would take to to a larger body of water and the other slack would just take you back to you're starting point the later may be the only slack to dive. It's just depends on the local conditions.

 

[Joris]

LollyO, I don't know the waters where you are planning to dive, but if this is the first time you will be diving in tidal waters where you need to dive on slack tide, it may be wise to do so with someone who has experience with this.

With respect to the time to dive, I think gcbryan has good advice: ask local divers. They know at which slack tide (not) to dive. At some sites the weather has a lot of influence on the tides and the predicted time of a slack tide may not be very accurate.

 

[evensplit]

Fort Pickens is best at slack, preferably high, but low works too. Visibility is usually better around the high.

The tide change makes a difference as well. If there's a difference of a foot or more between high and low, the current will be pretty stiff. If the change is more than 1.5 feet, we don't bother even trying except at the slack.

 

[LollyO]

Fort Pickens is best at slack, preferably high, but low works too. Visibility is usually better around the high. The tide change makes a difference as well. If there's a difference of a foot or more between high and low, the current will be pretty stiff. If the change is more than 1.5 feet, we don't bother even trying except at the slack.

There is a difference of more than a foot.

Between an incoming tide and an out going tide there will be a point where the water is slack. The duration and nature of that period will vary depending upon the locale, the geography, the lunar cycle and all of that stuff. N

... You you have a slack before ebb at 7:48am and a slack before flood at 6:52pm. In general, ebb will be going out and flood will be coming in but it depends on the local topography in case there are local inlets or other narrow restrictions.

you want to dive it at "high slack tide". at high tide, it's just pulled in fresh water from the gulf and current is a minimal .... for the 29th, "high slack tide" is at 5:06am. (you gonna dive that early?)

So given the above, the best time to dive the Pensacola Jetties this Sunday is between 5:06 AM and 7:48AM . except the difference of more than a foot
A couple of more questions:
1. Why is it that only the midchannel reports shows slack/ebb?
2. There are several Pensacola Entrance points….which is the best one to use for the Jetties? (however I think only mid channel shows slack and ebb.

Tides for Pensacola Bay Entrance August 29, 2009.
Day High Tide Height Sunrise Moon Time % Moon
/Low Time Feet Sunset Visible

Sa 29 High 5:06 AM 1.4 6:25 AM Set 12:52 AM 63
29 Low 5:53 PM 0.1 7:15 PM Rise 3:36 PM

Pensacola Bay entrance, midchannel, 8/29/09
2009-08-29 00:43 CDT 1.97 knots Max Flood
2009-08-29 00:51 CDT Moonset
2009-08-29 06:24 CDT Sunrise
2009-08-29 07:48 CDT -0.00 knots Slack, Ebb Begins
2009-08-29 12:13 CDT -2.35 knots Max Ebb
2009-08-29 15:35 CDT Moonrise
2009-08-29 18:52 CDT 0.00 knots Slack, Flood Begins
2009-08-29 19:15 CDT Sunset

Pensacola Bay Entrance, Pensacola Bay, Florida
2009-08-29 00:51 CDT Moonset
2009-08-29 05:27 CDT 1.39 feet High Tide
2009-08-29 06:24 CDT Sunrise
2009-08-29 15:35 CDT Moonrise
2009-08-29 18:00 CDT 0.15 feet Low Tide
2009-08-29 19:15 CDT Sunset

Entrance, Pensacola Bay, Florida 30.3333° N, 87.3167° W
2009-08-29 00:51 CDT Moonset
2009-08-29 05:05 CDT 1.38 feet High Tide
2009-08-29 06:24 CDT Sunrise
2009-08-29 15:35 CDT Moonrise
2009-08-29 17:52 CDT 0.06 feet Low Tide
2009-08-29 19:15 CDT Sunset