Underwater photography is usually not for the average photographer. Being under water and carrying scuba and photography gears at the same time is not easy. Take photos under water is a demanding endeavour that requires specialised equipment and requirements.
To shoot underwater scenes, one has two options:
1. Get an underwater camera
2. acquire an underwater housing for a digital camera. This comes in several types. Some of the more expensive types are made of hard plexiglass. The least expensive ones are usually soft plastic casings. One example of an underwater camera housing is FxF50.
One of the most critical issues concerning underwater photography is that of light falloff. Light falloff is very significant underwater. Once underwater, the amount of light decreases very dramatically. To overcome this, one will need additional supplementary light to illuminate and expose nicely. This additional light can either be the in-built flash on the camera or an accessory light. Usually, an accessory light can cast light further than in-built flashes. One company that makes reliable underwater photographic lighting equipment is Nocturnal Lights.
The other significant problem pertains to handling the camera while swimming/snorkelling/diving at the same time. One has to keep the camera water tight and dry. Because of this, one must first and foremost, be a good swimmer and scuba diver in order to deal with this additional problems of equipment handling under aquatic conditions.
From this article, we can see that taking professional photos under water is one of the most demanding photography type of all.