St Andrews Jetty Question ?

[Hetland]

Hetland,
Could you explain the tip on ending dives before end of high tide?
For example, if the chart shows high tide at 9:00 am, when will be end of high tide?
Thanks for information.

The "correct" answer to your question is: I don't know

Tide charts are basically predictions based on the phases of the moon, which control the tides. The actual tidal changes are a little more complicated, and are also based on currents and wind driven waves, which can be affected by something simple like local wind speed, or something more complex like melting snow increasing river levels, and therefore the volume of water flowing through the pass from rivers upstream. Tidal movement from lunar factors alone are not uniform either. You may have more volume moving in the first few hours, tapering off, and increasing once again towards the end of the cycle.... In other words, there is no one, set answer.

In practice, I find tidal predictions pretty accurate, so if high tide is predicted at 9:00am, I PLAN to be ready to leave the water at 9:00, but usually there is a period of time, where the water is at it's highest point, and current is slack (neither flowing in or out). We call this "high, slack tide". This is usually the sweet spot of shore diving. I've seen slack water for hours, say the lunar tides are falling, but there is an offshore breeze "pushing" those falling waters back into the bay. I've also seen gradual drops in visibility and severe drops 30ft to 1ft in a manner of seconds. Same with currents.

The important part is to have an idea of when and how conditions will change, and to be prepared at any and all times to navigate your way back to safety with bad viz and heavy current. St. Andrews is very forgiving, big wall always on one side or the other, plenty of hand-holds, etc. but I've had to use a compass and flashlight once or twice at Ft. Pickens (and travel hand-over-hand from rock to rock) in order to get to a safe exit.

Sooooo.... Pretend high tide is at noon at St. Andrews. Most folks diving aluminum 80's will get a maximum 45 minutes per tank, with 20 minute gear-ups and tank changes, so that's 130 minutes plus another 10 for your pre-dive condition review and discussion, so two hours, twenty minutes. I'd have my car parked at 9:40am YMMV.

I usually get longer dives, but I dive steel 100s, and can change a tank pretty fast. I still build in extra time in case I have a piece of gear fail, or there is an extra long line at the gate. You can never over-plan or over-prepare, even in recreational shore diving.

 

[jhayes75]

The best way to find your entry point is to bring a bright colored rope of about 45 ft. Put a weight on each end, leave one end on the kiddy side and bring the other end down to the sand. This way you will have an acent and decent line.

 

[RaginCajun]

For those times when high slack tide is fairly early and the park opens at ~8 am?

Do you know if annual state park pass holders can get the gate code to enter St. Andrews park early? Aside from getting it from a camper is there any way to get the gate code otherwise?

 

[idive2]

What is the depth at the bottom of the jetty at this cut through location ? Does this jetty
meet a sand bottom at the bottom ? Also do the depths along the edge of the jetty
get deeper as you move toward the ocean or is it kind of a constant depth on the edge of the
channel. Would weighting a yellow poly line attached to a flag with a pretty good sized weight in a location
a few feet out from the exit location work ? Or would it be better to secure to some structure below ?
We do a lot of bridge and shore diving down here but not much jetty diving. Thanks for any extra info or
suggestions.

 

[Wayward Son]

when you cross the rocks & drop down, you'll hit the channel at 40 - 45 FSW. It gets shallower to the left (back to the bay), deeper to the right (to the gulf).

I dunno what max depth is, but when I turned the first dive saturday due to another diver being low on gas I was at 70 FSW.

My normal MO is to cross the rocks, drop down (hugging the rocks in case of current) and then turn into the current. Dive as deep as possible until gas hits turn point, turn, work up to a shallower depth and work my way back to the gap.