dumpsterDiver
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Y'all are both right... and saying the same thing, sorta...
As a physics problem, unless the wind is blowing a couple hundred miles an hour, a diver on the surface with only his head above water will not have enough sail area to be wind driven, and will pretty much go with the current.
But... if a surface wind blows for long it will create a surface current moving in the same general direction as the wind, even if there is a substantial current running in another direction just a few feet below the surface.
It isn't unusual for the Gulf to be running more than one direction at the same time, especially in the area from Mississippi to Appalachicola. The generally clockwise open ocean current along the Gulf coast is interrupted by the Mississippi River peninsula (South Louisiana), and the current near the coast of Alabama and the Florida panhandle is filled with moving eddies that make the currents unpredictable, often layered and running in different directions, and sometimes strong. I have seen one of these currents roll in along the bottom like those pictures of approaching sandstorms in the desert, driving visibility from wonderful to awful instantly, and the water from calm to "hang-on-to-that-line-or-be-swept-away."
In the northern Gulf, when folks ask me "how much current will we have" on a dive I always answer "I'll let you know when we get back." Also, a strong current on the surface rarely means a strong current on the bottom, and no current on the surface doesn't guarantee a calm bottom.
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FWIW, on one Oriskany trip earlier this summer, the wind was running out of the South about 10 kts; surface current was running East fast, much faster than I could swim, and it was a job hanging onto the down-line and getting under, pulling hard hand-over-hand. Several divers on the boat never even got down at all. At 18' the current suddenly went to dead calm, down to about 40 or so, where it picked up a mild westerly drift down to 150 (as deep as I went that dive). A "free" ascent with deco stops would have carried me a bit west for awhile, then stationary, and if I had to spend any time at 10' I would have been rocketing East... it was a good day to plan the final deco stop at 20', as a 10' stop would have to be made "flag" style hanging on a line.
Rick
We drift dive in Palm Beach and all too often divers are "lost" for some time period as they drift off while on the surface. Although the currents are pretty predictable here, they do vary in time and place and a diver on the surface IS affected by the wind, but much less than a boat.
One method to track a lost diver on the surface is to rig a surface current drogue. Take a large float ball, tie 6 feet of rope to it, hang a weight belt or two from the rope and then tie a towel or two to the rope. This device should effectively mimic a diver drifting at the surface and being subjected to the prevailing winds and the surface current.
The current drogue can be carefully monitored for say exactly 10 minutes via use of the GPS.. all that is really necessary is to press MOB upon depolyment, back off for 10 minutes and get the bearing and distance at the time of pick up. You get a speed and a drift vector. Or the boat could carefully follow the thing being careful not to shield it from the wind and you can get the speed and direction by just staring at the GPs.. no calcualtions needed.
then you make a table which plots the starting location at time zero when the diver should have surfaced and then you can figure the distance at say half hour increments and using the drift direction, you can position the search vessel at the predicted locations over a period of several hours.
The drogue deployment should probably be done again a few hours later at the predicted location to help account for variation in conditions.
i heard a friend of mine drifted for several hours this week on the surface until the USCG found him and his buddies off Tampa.