2dive4fun, there was a very informative thread you started and posted in a while back..
I think this is it -
http://www.scubaboard.com/showthread.php?t=128284
As for my personal settings, don't know if it will work quite as well for the sort of water you dive in.
But FWIW I shoot almost exclusively in TV/shutter priority mode with a basline of 1/160s, although I really should increase it to something higher if i'm shooting upwards and trying to get a darker blue to the water.
Before I shot almost using exclusively using the u/w white balance mode which to be honest isn't as bad as you might think, but nothing can compare to setting white balance manually at the depth that you're shooting at.
I've got some great results that way..., such as.
Think this is far better than anythig I could have done in Photoshop
As a starting mode, i'd move away from program/auto modes and try TV or AV modes, although I would recommend TV mode as the effect that changing shutter speed has on pictures is a little more intuitive to me at least than changing the aperture value.
Keep practicing and that's a very good photo of an urchin there.