Cold shoe GoPro mount kit
Get that GoPro in sync...!
You can mount your GoPro in many ways... but if you already have a housing, the smartest way is to centralize it on your existing tray system.
This way you control the filming 100%.
The KIT consist of a cold shoe armball, clamp and a GoPro armball.
A good idea is to move it a bit forward on your housing, to avoind that the wide angle "see" the port of the housing.