Nikon D3

Although I have a D3x, I use the D3 topside (although excellent underwater as well of course). The fast frame rate is great for handheld HDR series shots.

This is a fantastic camera! The quality of images taken are next to nothing, above and below water. It is extremely good in low lighting, fast frame rate and great continuous focusing. Although bulky and quite heavy which sometimes makes it impossible to take photos inside nooks and crannies without damaging anything, I've accepted this and do my best with my 105mm lens. It's easy to review your shots underwater and the Subal housing allows everything to be accessible. Don't think I'll be changing any of my kit in a hurry!

Forgot to add that battery life is incredibly good and the facility of having two slots for memory cards means you can shoot in RAW without worrying about running out of space. All the better to avoid having to open up your housing too often and reducing risk of accidents.

Incredible at high ISO, the best I've seen on the market so far. Useful for wideangle in low light eg. deep wreck photogarphy, or for capturing fast moving subjest like dolphins. For close-ups you have to watch the depth of field - not as good as DX format so you may be better off with the the D2x.