What is the fastest shutter speed under water?

I will be using the compact C-5000 digicam for snorkeling in the St. John (USVI) waters this fall. I think the max ISO for this camera is less than 400. In those waters, what is the fastest shutter speed (without flash) I can expect to use on a sunny day, given the ISO range I will have? Again, we will only be snorkeling in shallow waters.

Thanks.

Shallow water snorkeling w/ a compact camera at ISO100 F4 you should be getting around 1/500th of a second or so.

Cheers

James

James,

So there will be plenty of light to freeze the action. Shooting with available light in shallow waters, do you think it would be necessary to use a red filter? At what depth do the red wavelengths start to "disappear"?

My compact digicam has custom white balance. So I should be able to use a white card to get a pretty good reading, I would think.

Thanks.