I used to have one of those Olympus Mju700 underwater/shockproof ones and to be honest the image quality was CRAP! The images on my old Canon Powershot A80 that I have a 40m depth waterproof case for absolutely smashed the Olympus and it only had half the megapixels! The Olympus one has the worst image sensor for digital noise I have ever seen in a digicam! Even in good light there was visible noise in the images. I personally would not get another Olympus after that experience.
On the weekend I was using a Canon Powershot D10 (canon's underwater offering) and it takes brilliant pictures in all light conditions. Its video is unbelievably smooth and is only limited in length by the size of your memory card. I dont know all the details on it but I gotta say I was pretty impressed at the video I got with a turtle at Cook Island. Even coming up out of the water when he was coming up for air, the camera changes the apeture quickly for the changing light conditions.
Check it out here:
http://www.canon.com.au/products/vis...ershotd10.aspx