Shore Diving: Tides and Currents

[Farra]

Main Question: When is it safe to shore dive with tides?

I am advanced certified and have only done boat dives. I have recently moved near the beach and I want to start shore diving more. I have done some basic research and have figured out that high tide is sully the best time to dive during the transition stage where the water is still. I know this ranges from about 1hr on either side etc., but at what point (tidal range & tidal current speed) do you need to worry about how strong the tide current is? the place I'm looking to dive (Ft Pickens in Pensacola, FL) only has a tidal range of about 1ft to 1.5ft (~0.3-.5m) with what appears to be 1-1.2kt current. Is this significant enough to worry about? The park opens at 10am, and the high tide is at 9:30am, with there being only 1 high tide and 1 low tide each day (low tide at about 9PM). Thus, the entire day is from high tide --> low tide. I also know local information is the best way to go and I plan on doing that research. My question is what is the general rule for tidal ranges, tidal current speed, and times of tide for safe scuba diving? (i.e. 60min on either side of high or low tide, or anywhere between 60 min before low tide till 60 min after high tide-assumption being the current would be pulling me to shore so as long as I can swim out against it the current shouldn't be a problem)

I have looked for a book or certification book I can buy on Amazon or eBay without any luck. Any personal knowledge or links to resources would be greatly appreciated!

Thanks!
-Farra

 

[Farra]

I'm not sure how well you can see these, but these are the specific diving tides and current for the nearest center.

 

[clownfishsydney]

I think you need to find someone with knowledge of the area you want to dive. For example, for the majority of Sydney shore dives, it does not matter when you dive as there are no currents produced by the tides. However, there are a couple where dives are better on incoming or at high tide, a couple where you could get in trouble if you dived on an outgoing tide and one where you must dive at high or low tide.

 

[Farra]

Thank you. That seems to be the overwhelming thought by everyone and I plan on doing that before every shore dive I do.
However, is there some sort of standard for dealing with tides to get an idea on the difficulty or intensity of a tide current, etc. in regards to tidal range, current speed, and time of tide (high/low/inbetween)?
Surely there is some standard protocol out there from one of the dive organizations (PADI, NAUI, SSI, etc) on a website, a book, or in someone's personal experience. I can't seem to find any general rules.The closest I found was this website: Tidal Currents - Diving Nelson Bay
Any opinions on the info presented there?
Also the tide times, tidal range, and tidal current I got from here: Tide/Current Predictor

 

[Agility]

Tides can vary from under 1m differenc between high and low tide to > 9m in some regions.
And the topography dictates the flow rates of the tides.
For these reasons there cannot be any standard.
Planning your (shore) dive around high or low tide to avoid fast currents is prudent.
ALWAYS get the advice of locals!

 

[Farra]

So if a tidal range is less then 1m difference, could it still be dangerous to dive mid ebb?

Also I read that an average diver can swim 0.8kt comfortably, so would anything with less speed than that be generally ok to dive in?

 

[Basking Ridge Diver]

I echo what was said on getting the local knowledge. Generally in the northeast I am in the water about 1 hour before high tide - that gives me generally 1.5 to 2 hours of shore diving - generally shallow waters and around here high tide is the best visibility so I can ride through that cycle - some areas have inlets. The high tide is less slippery on rocks or ramps (you can wade in and float over the slippery areas) as well as it gives me more water to swim in - all good things from my perspective.
But like everyone said you can not predict currents on any single day - that would be the outstanding local factor.

 

[Storker]

Tides can vary from under 1m differenc between high and low tide to > 9m in some regions.

While currents can vary from zero to tens of knots, with practically no correlation with tide levels. It's all about the topography.

ALWAYS get the advice of locals!

This. There are sites around here where viz is the only factor determining whether I dive at high, or low, or rising, or falling tide. There are also sites where I try to time my dive with high, or low, or rising, or falling tide. It's all about the topography.



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[geoff w]

For shore diving, in general you want to dive at slack tide, i.e., around high or low tide when there is the least water movement. An incoming tide before high tide usually brings in clearer water from deeper areas, whereas an outgoing tide will drag sand off the beach and visibility is less. In general, but there are a lot more variables. New and full moons usually produce bigger tidal swings, and less water movement creates lower tidal flows. Again, in general

You should check with some local dive shops and see if they offer either free fun dives from shore, or will provide a Discover Local Diving from shore, or do certification dives from shore. If they all say no, you might want to ask why, whether it's no interest or none of the local spots are any good for shore diving. Any local dive clubs? They can probably help you out too. Same with lifeguards at beaches you're considering

 

[TSandM]

A fairly good rule of thumb is that a diver can swim against a half knot of current, but that's assuming a reasonably fit diver with a good kick. And that's working hard for most folks.

We have a lot of tidal currents in the PNW. We definitely try to dive on slack, and look at the exchanges -- it's not just when it's high or low, but it's whether you are going from a large ebb to a small flood, or large to large. Some sites, we dive with the intent of going with the current until it reverses, and then allowing it to blow us back -- but you have to have ENOUGH of an exchange to do that.

Honestly, when it comes to diving current-sensitive sites, there is NOTHING more valuable than input from someone who is familiar with the place and how to dive it. Currents can behave in ways you wouldn't predict on paper, with eddies and reversals that are predictable but only if you know the topography.