Glittery Dawn at the End of a Season
The Mainiac Triathlon
The Mainiac Tri in Biddeford, Maine is a September end-of-season ritual where triathletes give it one last swim-bike-run prior to the frigid waters of Fall and Winter. Most are local athletes and it is a fairly small event (there were only 125 finishers in 2016) so it has a bit of a Norm walking into Cheers feel to it. All friendly, mostly familiar.
... and kids do what they do best prior to the race.
Many athletes "warm up" in the sunny waters before the race start ("warm up" is relative of course, as wet suits are just about mandatory).