I recently bought a small Sanyo CA9 video camera and devised a very simple rig which screws into deck fittings.
This is a VERY rough video, showing the shot I could achieve with the camera mounted on the furthest most fittings and the nearest. As you'll see, the big problem is the lens just isn't wide-angle enough for what I'm trying to achieve. Nor is the small lens very good quality. For fast video in HD it's great, but not for a boat mount I fear.