DIY GoPro Video Rig
A quick look at some possibilities for building your own underwater video platform for as little as $10. All parts are common (schedule 40) PVC pipe fittings with the exception of the gray conduit junction, which is a piece of electrical grade PVC. Threaded PVC fittings allow for the rig to come apart in key locations. The light mounts, for example, thread into the top of either handle, allowing removal and quick swapping of lights or accessories. An important note: you must have at least one decently large opening for venting air and draining water.
Normal rigs provide a two-handed grip to help stabilize the camera but this design incorporates a removable arm brace to eliminate instability due to wrist movement and greatly aid in one-handed shooting. If you fancy a simpler design or want to work on something simpler as a starter project, check out this other rig instead.