I have modified this rig to provide 6 gopro camera's around the center of the rig, and two gopro's which will be angled up. Gopro's are mounted in their waterproof housing.

The 8 gorpo's are required because when you are recording underwater, the field of view get's reduced by about 33% - enough reduction to no longer make your video's overlap, thus not stitchable on a traditional rig like the freedom 360, or even gopro's new omni.

There are two mounts on the camera - one external classic gopro mont (underwater selfie stick holder), and one 1/4 classic tripod mount.

I've used this for aerial photography on my drone. you can see an early video here: https://vr.gopro.com/video/201c92ba737ccd314f782280dd1d4a88

I will be testing the rig in Cancun in the beginning of June, and will post the video.