Hey, Trig-guy. Ask yourself a few questions before buying a videocamera, digital SLR, or digital point-and-shoot. First off, a digital videocam will cost you a lot of bucks, and if you want to take still photos from it, you're gonna have less resolution than a cheap point-and-shoot. Unless, of course, you're willing to spend a lot of money on pro equipment with triple CCD's. Trust me, I went thru the same decision making process several months ago, and technology hasn't changed much since then... So, ok, go the cheap way, and buy a point and shoot digital such as the canon 620, which also has video capability. In the video mode you will get 640 x 480 pixels in the standard mode, and less in other modes. It looks great during playback, but most of your dive buds and other viewing friends couldn' care less about your 10 minutes of video time underwater...they want the hi-res single frame images of things that you've seen...been there. But do you actually plan on using the 620 underwater in the video function? I'll bet 99% of us 620 users don't use the video function underwater, but I may be wrong. So, think about your end goal, cost, etc. The 620's still photos are amazing, for the price, but you'd have to pay 10000's more for a video cam capable of doing the same if you wanted to "extract" an individual video frame from your footage.
Best of luck -- Mach2plus
