Behold Olympic swimmer Ryan Lochte and Prince Harry third-in-line-to-the-throne-of-Britain racing each other in a Las Vegas pool over the weekend. Breaststroke, heads above water. See for instance Popsugar and the NY Daily News
Here is another video also showing the start, apparently there was a third swimmer also, maybe the judge?
Later, Prince Harry also wrestled a girl while naked, footage confirmed by the Palace, so I guess he won the duathlon.