Dayum.
A question about whistles though: The orange whistle in that video was flat, what I have seen other 'safety' whistles shaped like. My opinion though, is the only kind of whistle to bother with is a Fox 40. That's the referee whistle and it doesn't have any ball inside it. (Not sure about that flat whistle). Sports refs use it because it does not fail. My personal safety whistle, in my case mostly for things like hiking solo, not the water, is a mini Fox 40, with the same shape as the normal one, just smaller. I did test it when I did my scuba checkout dive though. One part of that test is trying the whistle, and I used both the whistle that came with the dive gear, and then my mini Fox 40. I had a hard time getting the standard whistle to blow, but the Fox 40 went off with a super loud blast no problems. People probably tend to want to save money on an emergency whistle, since it is hardly used, but obviously if you actually need to use it, it is critical.