Water tested and took the gopro hero 2 hd camera set up with the Pursuit flat lens and tried it out yesterday. Video is pretty boring because there weren't any wsb or halis around so I didn't spear anything but I took some vid of reef fish. Visibility was exceptional at 20-30' in the deeper spots.
The one thing I didn't like was the head strap lets a thin stream of cold water under my hood and I could feel it trickling down my back! I think I'm going to get a gun mount next time.
GoPro HD Hero 2 camera with Flat Lens underwater test - YouTube