Tides and shore diving

[murdrcycle]

I am from the Midwest US and don't have a lot of diving experience anyway, but I am going to Destin, FL for a week this summer. I see that there are plenty of shore diving opportunities, but everyone keeps talking about consulting tide tables.

Well, I have looked and realized that I don't know what the heck I am looking for. Being from the Midwest, I don't do a lot of diving in tides. It is either quarries or from a boat in the ocean. I did shore dive twice, but it was led by a divemaster (a "discover scuba" type of thing).

So my question is what should I be looking for in a dive table (I see high tide and low tide, but which is better? Does whether high tide or low tide is better vary by location)?

I intend on consulting a local dive shop when I get there for up-to-the-minute details, but I wanted to ask this question a few months in advance just in case it is one of those concepts that can't be fully learned in a discussion with a local dive shop operator.

 

[300bar]

Not sure on the diving overthere but normaly you'll be diving at slacktide.
the time the tide changes from either high or low.Depending on the strength of the tide,you'll have a surtain timeframe(window) to dive.

Do get the local info for any tidal site.Some are very easy,others can be major problems.

have some great dives.

 

[perdidochas]

I am from the Midwest US and don't have a lot of diving experience anyway, but I am going to Destin, FL for a week this summer. I see that there are plenty of shore diving opportunities, but everyone keeps talking about consulting tide tables.

Well, I have looked and realized that I don't know what the heck I am looking for. Being from the Midwest, I don't do a lot of diving in tides. It is either quarries or from a boat in the ocean. I did shore dive twice, but it was led by a divemaster (a "discover scuba" type of thing).

So my question is what should I be looking for in a dive table (I see high tide and low tide, but which is better? Does whether high tide or low tide is better vary by location)?

I intend on consulting a local dive shop when I get there for up-to-the-minute details, but I wanted to ask this question a few months in advance just in case it is one of those concepts that can't be fully learned in a discussion with a local dive shop operator.

Ideally, you want to dive between an hour before and an hour after high tide. That is when you have the best visibility and least current. On a beach dive, it's not too important, but if you're diving the Destin jetties, it's critical. The current through there can blast. Talk to the dive shops for their recommendations.

 

[dpbishop]

Tides effect diving in three ways: visibility, current, and depth. Tidal flow is greatest midway between the high and low tides, for 20 min. either side of the high & low it is slack water (no tidal current). The greater the difference between the High & Low the stronger the current. Tidal currents are usually negligible along open beaches, but can get quite strong in narrow passages.

Visibility is usually better at slack water and on incoming tides.

Depth is a factor on shallow dives, and when entering and leaving the water at rocks or cliffs. Southern California has a maximum tidal swing of 9 ft. +/-. That means the beach you went in from might not be there when you exit. Florida's tides aren't as extreme ( 4-5 ft range ) but they are still worthy of respect.

You should also check with lifeguards or other local knowledge when shore diving at a new location for information on rip currents. Tidal & wave action can create localized flows that will carry even a strong swimmer away from the beach. (note: if caught in a rip, swim parrallel to the beach until you get out of it, they are usually only a few hundred yards wide at most.

 

[H2ODog]

The tide exchange, location and topography influence the water movement in a given area. The greater the exchange the greater the water movement and the more importance diving at slack becomes. Here on the west coast, we'll dive bay jetties and during a 5' tide exchange it can get pretty hairy with the water movement and low vis in some areas.

Search the dive shops in the area you're planning to go and inquire about local shore diving, where to go, local hazards, etc. and then form a good plan. It could greatly increase your enjoyment level to hire a local divemaster as a guide for a dive or two. If after the dive, you find out that it wasn't worth it, don't hire them again. It's kind of like insurance (which I hate), good to have around when you need it but hope you never need to use it. I'd rather pay a little extra to ensure I have a good experience rather that hope for the best only to have a bad experience to worse an accident.

My .02 for what I'd do.

 

[perdidochas]

Tides effect diving in three ways: visibility, current, and depth. Tidal flow is greatest midway between the high and low tides, for 20 min. either side of the high & low it is slack water (no tidal current). The greater the difference between the High & Low the stronger the current. Tidal currents are usually negligible along open beaches, but can get quite strong in narrow passages.

Visibility is usually better at slack water and on incoming tides.

Depth is a factor on shallow dives, and when entering and leaving the water at rocks or cliffs. Southern California has a maximum tidal swing of 9 ft. +/-. That means the beach you went in from might not be there when you exit. Florida's tides aren't as extreme ( 4-5 ft range ) but they are still worthy of respect.

Destin (Gulf of Mexico) tides are 2-3 ft.

You should also check with lifeguards or other local knowledge when shore diving at a new location for information on rip currents. Tidal & wave action can create localized flows that will carry even a strong swimmer away from the beach. (note: if caught in a rip, swim parrallel to the beach until you get out of it, they are usually only a few hundred yards wide at most.

Rip currents can be very useful for a diver. It's a good way to get out deep without swimming. Most rip currents end past the last set of breakers.

 

[Scottri]

Go to any fishing store or sporting goods store and they should sell a tide table. It's usually a small booklet that has the high and low tides for the entire year. Usually only a couple of bucks.

Here in the Northwest we can get tidal exchanges of 15 or 20 feet sometimes and you can get some RIPPING Currents. Some sites are off limits in those conditions and other are not much affected. Tides and geography have a big effect on currents. The further south you go toward the equator the less the tidal exchanges. In Hawaii they are usually only a foot or two. I always plan my dives near high slack when possible but low slack can be good at some sites.

Good luck and talk to a local fisherman, they can usually give you a good introduction if you can't find what you need at a diveshop.

 

[Saltwater Junky]

Didn't know about slack tides. I've read visbility is better at high tide. I'll plan future dives with both slack and high tide in mind.

 

[seaducer]

One thing I didn't see mentioned, make sure you know the tide for the area you are diving. Typically the table will list one set of times for a location, but you need to correct for the specific spot you are diving.
For example here in NJ the high tide may be listed as 12 on the chart, for Seaside Park. There will be corrections listed for Barnegat inlet + :20 and Manasquan Inlet - :15

That means if you are diving Manasquan Inlet you want to plan for the high tide to be 1145. It will also give you another number, perhaps a 4.3 or a 2. That is the amount of rise or fall the tide is predicted to move. Note that storms and droughts and even wind can effect that number. Off shore winds for example can make the tide lower than predicted, heavy rains, even inland can increase it, often with decreased visibility.

Mostly for shore diving you want to dive high slack, that brings in (hopefully) cleaner clear water from off shore, as opposed to low tide which often pulls sediment laden water from bays and rivers. Someone mentioned that the amount of slack tide is 40 minutes, IE 20 minutes on each side of the tide, well that is not always true, it can vary from location to location and again, it is the time of the tide in your specific location, not the number in the chart.

Also the external effects that work on the tide, such as moon phases, wind, rain, etc, can lengthen or shorten that slack tide window.

You best bet is to contact an LDS where you want to dive and ask them for recomendations. Not only will they tell you the best sites to dive, but can give you an idea on the times you want to dive them as well and also any special conditions not listed on the chart.

Sounds like a lot to consider, and it is, however it is also not that hard to figure out once you understand what tides are and how the work.

 

[mike_s]

In Destin you'll want to dive at "high slack tide" for diving "East Pass" Jetties.


why High slack tide over low tide?

Well you dive at slack tide because it reduces the current to the lowest amount. Makes for a much easier dive. You chose High over Low for visibility. At high tide, the water in the pass is 'fresh' ocean water sucked in from the incoming high tide. at low slack tide, the water in the pass is 'outgoing' bay water that is brackish, full of silt, etc and has poor vis.

www.saltwatertides.com provides the tide time for East Pass.