Shooting underwater can be great fun, and has the advantage of taking the viewer outside the realm of their normal vision, so if your image quality isn’t so hot it still looks special. Commercial waterproof enclosures tend to be rather expensive, but they’re not your only option. My first underwater shoot was a security camera on a PVC pole connected to a VCR; ghetto technology but it looked great. Slightly more advanced but still along the PVC kick is this project via Make:Blog.
I’d like to see a version of this mounted to a pole for dry operation and viewing. Add an IR remote repeater for start/stop and zoom operation, and you can yell at your talent from the outside of the dark, freezing pool while you shoot your own take on Portishead – Only You:
Plans and instructions are on Instructables, along with some rather insightful commenting.