A said something about scrabble on the beach and a fight in a thread directed at me. Some things you can't stay away from...
QUOTE (xbwolfx @ Sep 16 2009, 07:23 PM)

iirc, you have an underwater housing for your G9.
what settings do you use?
do you just use the underwater setting, the P setting, or what?
So I've found that shooting underwater with this thing is a pain because you can't access the dial that changes settings. I end up going with more of a shotgun approach. It's annoying at the beginning of the trip, because you'll spend 5 minutes adjusting settings, but after that first trip out, you'll have the settings you want to use.
Set Tv to 1/100
Set Av to f/5.6
I also...
Set Manual to whatever the camera settings are in automatic when you take a photo of the water from the beach, and then go a couple of stops slower on the shutter speed or lower on the f-stop for snorkeling, more if you're going down more than a few feet.
Set the custom settings - one a bit slower, one a bit faster than whatever you set on Manual.
...but these you can *probably* be okay without.
Then...
Take some shots once you get out in the water with EV between 0 and -1, ISO 200. Once you find a good setting, stick to that and adjust EV and ISO to control the photo.
I've found that the underwater setting on the G9 isn't so great, not sure on the G10. Automatic is horrible - extremely high ISO.
It's a bit of a pain to set up - a few minutes of button fiddling, but it'll get you there. After the first time using it, you should have gotten a close enough setting that you won't need to mess with it anymore. Then you just stick to that setting, and adjust EV and/or ISO to adjust for depth/clouds/etc. Oh, and definitely want to use RAW or make sure you white balance. RAW is best here because you can underexpose the pictures a bit to increase shutter speeds without losing a lot of quality.
Good luck - it'll take some practice before you get nice shots from it, but you'll get it.