There are massive problems associated with taking shots underwater, but the rules of the great dry-land photographers can still apply. These include:
Your first 10,000 photographs are your worst. – Henri Cartier-Bresson
The quality of these shots is low due to the camera. Get a better camera with an underwater housing if you want better shots.
These were taken in the maldives using a cheap disposable underwater camera.
However, Digital Cameras with underwater housings are now proving to be a great tool for underwater photography.