For snorkelling, I bought an Olympus Mju 770 SW a few years ago and last year, it decided that it would no longer be waterproof. To replace it, I've now got a Canon D10 which has yet to be tested (by me) in the briny, although we're off in 2 1/2 weeks to somewhere warm enough for me to get in the sea with it! I'll report back on it's underwater IQ etc once I know more. It's only waterproof down to 10m though, so only really good for snorkelling, not diving.