?? camera settings for our green water

[Roger Southwick]

Fred,

Depending on what you're trying to photograph, here are some suggestions.

Small objects shot from close range:

Use the strobe with diffuser if possible.  An on-camera flash can give lots of backscatter though; an off-camera strobe would be better.

Try to get close; zoom in only if you really need to.  Use the macro setting for really close focusing.

For the white-balance setting, use daylight or flash since most of the light will come from the flash (the daylight and flash settings are almost the same anyway).  Using automatic white-balance could give widely varying results depending on what's in the frame.  Don't use the "underwater" setting with flash, or things lighted by the strobe will probably look very yellow / red.

Big-picture scenics or divers:

If you want the scene to look like what it really is, set white balance to daylight.  The resulting photo will probably look more green than they appear to your eye while diving, so you might try automatic white balance too -- but AWB can over-do it.  (The nice thing about digital is that you can try them all while underwater and see the results.)  The "underwater" setting might help, but I think it's made for removing the blues from tropical-water shots, and we're diving in green muck.

Flash won't be helpful at more than 3' away, so turn off the strobe and use ambient light for those shots.  Otherwise you'll probably just get bright backscatter and a dark subject.

Try to use the widest zoom setting possible, and get close.

Think about doing silhouettes of divers, boats, and other objects that can be recognized by their outline.  Don't use the strobe, and shoot upward so the background water is bright.

Try to avoid shooting downward; shoot horizontally or upward so there's a nice plain background of water on which the subject can stand out.

Ambient-light shots work well when converted to black & white.

Most of all, have fun with your new camera and post some results when you get back!
-- Roger