I love these type of videos - the more artistic flavor kind.
They is something very calming about watching the flow of skin ripple through the water and the hair flowing behind with some great music in the background. Sort of like watching the flames from the fire bend and curve; just at a slower pace.
With that said, the first thought that came into my mind was 'damn, these two have amazing lung capacity!' lol.
I hope to one day experience the same freedom of swimming sans clothes with exotic fishes and whales, etc.
Living in NYC and having shallow pockets, the closest I'll get is if I drop my drawers and walk through the fish market.