Every year, the March of Dimes sponsors The Great Chesapeake Bay Swim. This was number 21 and the sea kayaking group I belong to does the safety (kayaks are the only boats allowed near the swimmers) - - to assist swimmers in trouble or give them a resting platform.
(photo: DJ Manalo)
The swim (4.4 mile) is always oversubscribed and therefore is done by lottery (and all entrants must have open water and distance experience). This year there were 650 participants and the winner made it in less than an hour and a half !! No stats as yet on the open-entry one-mile swim.
I did safety for both the one-mile and the 4.4 mile (with a "biffy" break in-between) and ended up spending four hours in the boat.
Of course, any day on the water is a good one.