Agree with above, water above the reef and get lightroom. Use auto white balance and you can adjust the white balance in post processing. You can even tweak the exposure and contrast to some extent. That will help a little with color blow out. Get a decent digital camera, housing and a strobe, take lots of pictures and mess around with the settings. Shoot in RAW. RAW is lossless. Essentially, the information in it is each and every pixel in your camera. JPEG discards a lot of information which results in loss of clarity and digital noise. Cameras don't know they're underwater and most of the time, you'll get better photos when you adjust the settings yourself. Basically, higher iso (> 400) for darker situations and a lower fstop. With a higher iso you'll have to adjust the shutter speed (faster). My 'jump' settings are usually iso 400, shutter 1/100, fstop 5.6, strobe full power through the lens (ttl). I'm usually shooting in deep water. I began in full auto, then I started shooting in aperature priority and adjusting iso and fstop, and the quality of my photos improved. Composition is a different story. 
