Would suck to swim through an invisible hypoxic zone and pass out or clog from all the funk in the ocean. I'd catalog this one with the rebreather helmet. Not practical.
Edit: I saw this contraption a while back and wrote it off, but perhaps it will become a reality judging from the pool test video. Of course that video could be manipulated. Nevertheless, I see a lot of death written all over this. Something like those hover boards blowing up on people. I sure as hell wouldn't want to be an inexperienced free diver tourist, with weight and fins relying on a microprocessor and no depth gauge or training. Over under on how many people die in the first year?