Underwater Dancing: Mesmerizing and Confusing

Underwater dancing is not yet an Olympic sport, but with any luck it soon will be. It’s a lot like synchronized swimming, but these dancers are entirely submerged underwater while they perform. It takes a while to figure out what’s going on, since your brain just can’t compute the fact that the camera is upside down and the dancers are actually doing all of this underwater. It’s like watching a lava lamp. You just can’t take your eyes off them. Aside from the fact that they’re holding their breath for that long, how much strength must it take to keep your entire body submerged while performing perfectly boy-band-quality synced dance moves?