Hmmm, hard to believe you can't find
anything on these cameras, I think a
couple people have used them and mentioned it...
Ok, ok--"No snarkiness"!
A G-10 will be a bit tough to find and if you do find one they seem to have held their value. I really liked mine (until I drowned it) but compared to my G-12 it was a bit noisy (or grainy as we used to call it back in ancient times), especially above ISO 200 or in underexposed areas. The G-10 was a 14mb camera and the G-12 is a 10mb. Canon made a good decision on that change, overall I prefer the G-12 results. If you do any video the G -12 has HD (though no autofocus when in video mode). Either camera is great for macro, probably their strong suit.
I have an S-95 and enjoy it but got to use an S-100 for a few days in Raja Ampat (we won't talk about how I drowned my S-95). The S-95 or S-100 has HD video but the S-100 added autofocus & auto-exposure in that mode and it sure helps. Aside from their smaller size (housings are maybe half the size of the G housings) their best attribute is the ability to fully use a whole bunch of different wide angle wet lenses. The longer zoom range of the G series means they have to put the housing port quite a ways forward compared to S series housings. When you go to wide angle the lens actually pulls back towards the camera body and gets serious vignetting from the edges of the wa lens & port. You have to bump the zoom range up a bit to avoid it--and lose the reason for using the wa lens.
Given there is no real image difference between the cameras (at least the G-12/S-100) consider what sort of shooting might interest you uw. if you aren't sure, get the S-100. While it isn't as capable shooting close up on it's own (the camera's macro mode is not a match for the G series), as soon as you add a close-up lens you have plenty of macro capability. (The trick is swapping those lenses uw but that is another search.)
So, what's the answer for you? I dunno, I take both cameras on trips and try to figure it out on the boat! If I had to be sensible (spare me...
), I would get the S-100. (Please don't tell my G-12 that.) No real drawback, great P&S results and price-wise there are some hot bargains out there on it. The versatility and size make thre S-100 a cinch to recommend.
Last point. Plan on an external strobe at some point. Camera choice is one thing but adding an adjustable, external light source is critical for most good uw work. (Which is yet another search!) // ww
