This is my Dex Mini Quad frame. A hollow 300 frame which is buoyant!
See full review in http://blog.oscarliang.net/flying-quadcopter-under-water/
I've made a small hole to fit the lens of a board cam and fitted all the electronics on the inside. The camera is slightly lower then the water level when it lands in the water making it possible to FPV underwater!
Since the frame is carbon fiber, the antennas (flight and video) need to be located on the outside so, further holes are needed.
Under the frame there is an attachment for a gopro making it possible to film in HD underwater.
