Currents

[LI Diver]

Just a quick post before I'm off to work. I've never heard much talk of planning boat dives according to tide or current stages although I have heard many shore divers discuss this. Is this something done internally at the dive shop and not mentioned to the divers or do they just make their 2 or 3 scheduled trips, day in and day out and it falls as it may? I'm sure some dives are safer at slack water or on day's when there is less of a tidal change, right? Of course barring storm surges and such. Any thoughts or advice?

 

[TSandM]

Well, around Puget Sound, the boat captains have to know the currents well, because most of our sites are current-sensitive and if you drop people at the wrong time, they are going to have at best a bad time, and at worst somebody's going to get lost or hurt. And when I've gone out on my friend rjack's boat, we've definitely spent time calculating the tides and currents for the contemplated site, and making sure we get there when we're supposed to, or we don't go.

 

[Doc]

Depends upon the location- North Eastern US Dive charter or a day boat in the Philippines?

Boats depart on a set schedule to a great extent- sure, you can alter the departure times a bit, but still~ everybody's got to have breakfast, load the boat and after the dive, they want to be back at the dock in time for their next "appointment". If you have your own boat or are doing expedition diving, you can call the dance, but that would be the exception. You can't expect a great following if you announce the departure for 0400 hrs and the return will be at 2200. The little woman wouldn't buy it.

In destination resort areas, we travellers depend upon the considerable local knowledge of the DiveMasters. In places like the Galapagos, they do a whole lot more than point out Hammerheads for the terminally myopic.

In the Philippines, we knew to be on the dock at 0800, but at that point, the DM's really wouldn't know which precise place we would flop in. They had a general direction, but would do a lot of fiddling on scene before they would say 3-2-1-Go.

The DM would gently adjust the dive depending upon the flow he was seeing and also anticipating. We finally got our DM so well trained that he would look at the swirling, roiling surface currents, grin, and say, "Wanna see where it takes us?" (Of course, this is the guy who learned that the "out of air" sign really meant "where's the boat?")

When we look at diving here in the US at deep wrecks that border on technical efforts, of course we depend upon the expertise of the leader or DM. This is where trouble begins. Many times, we are just chartering a boat and directing them to take us out at 0800 and put us over the wreck site... whenever. Our buddy that arranged the trip becomes the defacto "dive leader". Does he have the understanding necessary?

Any doubt? Speak to a local expert, hire a local expert.

 

[MXGratefulDiver]

Just a quick post before I'm off to work. I've never heard much talk of planning boat dives according to tide or current stages although I have heard many shore divers discuss this. Is this something done internally at the dive shop and not mentioned to the divers or do they just make their 2 or 3 scheduled trips, day in and day out and it falls as it may? I'm sure some dives are safer at slack water or on day's when there is less of a tidal change, right? Of course barring storm surges and such. Any thoughts or advice?

It often depends on whether you're planning to do a drift dive or not ... and whether you're diving off of a live boat or an anchored boat. In some cases, an appropriate amount of current is desireable ... in other cases, you avoid it at all costs.

You tend to hear more about it for shore dives because the vast majority of shore dives involve exiting the water at approximately the same point you entered it, in which case you have to account for swimming against current, if there is any, at some point in the dive ...

... Bob (Grateful Diver)