On a boat! Water proof and shock proof are IMHO required. The olympus, while it won't shoot in "Raw" mode and the rate between click and pic isn't the hightest, it will last. Of course they say you can take it down 30' but those that have find it doesn't last as long and they have to get it replaced.

I've never dove with ours. I have droped it on blacktop while jogging down the road. It has gotten water on it a few times. It works great. Battery life it excellent, can adjust for lighting if desired, and has an "anti - shake" option great for on the boat. Also it's zoom is quite good with the lens.

You can't change lens'. You can't quickly change f stop or speed like on an SLR, and it doesn't shoot in RAW mode for the ultimate tweeking.

Just my 2 cents,

Go Slow
Sail Far
Stay Long