GoPro 3 Black gets stuck in ">" Play mode when diving I have bought a touchscreen backpanel for my GoPro3 black and whenever I take it diving, it switches to ">" play mode (the black triangle shows up on the front panel and keeps stuck there). I cannot switch it off or operate any of the buttons.

Can it be that the touch panel reacts to pressure from the back cover? I am not using the touch back panel by the way. Any idea what else can be causing this? I have the latest firmware.
It sounds like your probably correct about the pressure of the back panel activating it or possibly the conductance of the water that is around it.  It could be either depending on the type of touch screen they used.