If you have a digital SLR and don't want to blow two grand on an underwater housing, check out the alternative the folks at Digital Camera World came up with. Just put your camera into a clean fish tank, attach a remote shutter release cable, lower the tank into the water, and fire away. Naturally, this only works in calm water, so don't take it into the ocean unless you fancy buying a new camera.

Though the site mentions you have to take a lot of shots and check the results because you can't see through the viewfinder, it's worth pointing out that using an SLR with a swivel screen would allow you to compose while you shoot.

A Nikon DSLR in a fish tank starts its dive under the water. [Photo: Digital Camera World]

Feeling brave and want to try it for yourself? You'll find instructions via the source link below. And don't forget to make sure that fish tank doesn't leak before you take it for a dip!