Professional underwater photographer and good friend Tony Wu has written a post on his personal blog about shooting underwater with compact cameras. Tony took a Sony W300 down for some dives and set it on underwater white-balance mode. He managed to get some fantastic images!
… whatever the camera is doing, it clearly works. What this means in practical terms is that with just your compact digital camera and a normal housing, you can take nice, colourful photos. There’s no need to get fancy or invest in anything else.