This thing has not been tested, you are welcome to participate in proposing any improvements you see fit, and print-testing it (it is a big thing ~150g).
This rig will enable you to record 360 videos with 6 action cameras. This is the only rig of it's kind (that I know of) published in Thingiverse, that allows you to do so with all the underwater cases. So, in theory, you could use it to record 360 videos underwater!
It is designed to be used either with a 1/4" nut (for standard photography tripods) or/and triple GoPro compatible connectors (for use with any standard GoPro accessory).
This repository includes MoonCactus' GoPro Mount Librarty (licensed under CC - A - NC 3.0, work to which no modification is done) .
Probably the only parameter you will need to edit is the MaxCamDim parameter. It is set for 80mm wide cases (78mm + some margin), this parameter will make the rig smaller or larger accordingly. Make sure your case will fit by "debugging" a cube with it's dimensions (see debbuging towards the end of the scad file).
This work is licensed under CC - A - NC 3.0 license. See LICENSE file for more details.