First of all I hope you were holding a go pro on a stick and not diving on it! Looks like that bit of line is actually tangled up in one of the "working blades" but it is hard to see. Interesting video, I have never seen one of these in action.
Yea, I was thinking "Hey it must cold up there!" Not to mention the risk of getting chopped up. I kind of have an unnatural fear of propellers as I knew someone as a child who almost got his leg taken off. Well perhaps that is a natural fear! But that water must be cold. nice and clear though.Gopro is on a pole.