I am just back from a few weeks in Grand Cayman. Here are a gallery of pictures that I took with my Nikon S3. http://www.amustard.com/s3/
The Nikon S3 was not a camera I chose for UW shooting. Instead it was a camera for taking out and about with me. It is tiny and very thin. Its main use underwater is as a prop for models, which you can see in the first two images in the gallery - these were taken with my main camera. It is a useful UW camera because it is so small and the housing is so thin that it easily slides into a BC pocket.

I have one rule with the camera - I am not allowed to buy any external accessories. Compacts are capable of great UW pictures - but invariably this requires an external flash and external wide angle or close-up lenses. Which quickly make the system anything but compact, defeating the object of buyinig a compact in the first place.
So all these pictures are taken with the camera as is. The only accessory I used was a new filter i am developing. This filter is designed specifically for point and shoot photography - so works with the camera set on AUTO-WB. So wide angle was available light and macro/fish were with the internal flash. In clear Cayman waters backscatter was not much of a problem - but when tried in turbid seagrass areas, in the rain, backscatter was noticeable.
None of these pictures are cropped and PS processing is limited to AUTO-LEVELS. I am pretty pleased with the performance of the camera for snapshots, but the images are definitely noisy and to my eyes tend to come out of the camera with an over processed look.


These shots come from just a couple of dives - often taken with my D2X in my other hand - so they are not the greatest, but thought that they would be of interest.
Alex