ZCAM E2 water housing / monitoring options

[Pewwinck]

Hi there, 

I'm a happy owner of a ZCAME2 and i'm building a water housing mostly for shooting surfing. 

To keep the thing small and avoid the heat, i'd like not puting any screen in it. i just need to control the exposition and basic framing on the back of the camera.

I was thinking of a prism on the top screen of the camera to give me a viewfinder on the back side of the camera but perhaps you guys could have an idea.

anything if welcome.

Thanks a lot