Pretty sure the chest strap idea will not accomplish what you want, as your chest will rarely be facing the direction you want to film (assuming you are in good trim and not swimming like a seahorse). I would strongly suggest some sort of head-mounted option for hands free video. This will ensure you are always filming what you are looking at. I suggest a helmet mount, if you are willing to wear a helmet, as this provides not only stability but also a good place to mount lights to help improve the color of your videos. If you don’t want a helmet, then go with the headband mount. Either of these will give you a nice video of everything you look at by turning your head, without much of the extraneous stuff that you just check by moving your eyes (like checking your pressure gauge, looking down at clip off points, etc.). It has worked well for me. I video the whole dive and then edit out the boring parts (like swimming around mid-water where there is nothing to see) later.