When I teach photo workshops, one of the most common questions is, "How can I improve my images?" This is a big question, with a lot of answers. For some participants, the answer is working on a specific technique, such as using a tripod to capture tack-sharp images. For others, it's choosing the right depth of field for accurate selective focus. We all have areas that need improvement in our photography.
Housing OptionsMost cameras aren't waterproof and need a protective housing to work underwater. There are a few exceptions to this, such as waterproof point-and-shoot cameras, but most of us want to use our existing camera underwater, not go out and buy a new body just for underwater shots.
There are many underwater options, ranging from simple and inexpensive "splash" housings to advanced (and more expensive) dive housings that allow full control of your camera's functions.
Some of the simplest underwater housings that work with almost any camera are PVC housings by ewa-marine. They come in a wide variety of sizes that accommodate everything from video cameras to SLRs with speedlights attached. These housings work by placing your camera in a PVC bag and sealing the opening flap with a metal bar. You access your camera controls by pressing buttons through the PVC or using the finger slots provided in the housing. ewa-marine housings have an optical glass port to fit your lens and ensure clear images. They're waterproof from 20 to 150 feet, depending on the housing. These waterproof pouches are the cheapest option to waterproof your DSLR. For around $50, you can get a point-and-shoot housing, and for a few hundred bucks, you can get a DSLR camera housing.
Another inexpensive option is getting an underwater housing for your point-and-shoot camera. Companies such as Fantasea have numerous point-and-shoot housings for around $100. I use a Nikon P7000, a top-of-the-line Coolpix camera that produces terrific files. Fantasea makes a housing for the P7000 (around $400) that gives you full control of the camera functions, including flash and video.
The next step up are custom waterproof housings for your DSLR. These housing can cost more than your DSLR, but for serious underwater work they're worth it. These housings allow full control of your camera functions, and they're waterproof to depths of 300 feet and more, depending on the housing. These housings also offer sync terminals to use underwater flash systems. In addition to the housing, you need a lens port to match the lens you're using.