Bought a GoPro Hero black a couple of weeks ago. I have tested it in the car a couple of times, and decided to test it underwater today when I snorkeled.
The GoPro, for you who aren't familiar with it, is a very small video camera that also has a waterproof housing. I had mounted it on my chest, the recording was successful, but the camera was angled a bit too much straight down. Have to fix that next time.
Saw a sea turtle when I snorkeled, and got it on camera. The video is however to big, so the image attached here is only a small screen capture of one frame.