GoPros are well-known for being robust. I mean, we've seen one fall out of a plane and land intact. This GoPro was keen on going on its own adventure as well, except in the water instead of the air.
According to the video's poster, the GoPro fell off during the surf (as you get to see) and washed up in a tidepool seven hours later. Seven hours is a long time, so you can take your bets on whether she's just wrong about it having been seven hours or whether it's viral marketing or both. In any event, a GoPro could totally do this (if not for quite that long), and it's neat—though disorienting—to see. And as much as soundtracks to videos like this can be hit or miss, this one's a hit.
Cool or not, you'd be well-advised to keep your cam out of the ocean and under control; everybody needs to stop dropping these things. [Reddit]