About 200 divers and snorkelers submerged Saturday to listen to a local radio station's subsea concert in the Florida Keys National Marine Sanctuary.
Staged by WWUS, the Lower Keys Underwater Music Festival took place at Looe Key Reef, part of the continental United States' only living coral barrier reef that lies about six miles south of Big Pine Key.
Music broadcast by the station was piped beneath the waves through waterproof speakers suspended under boats.
"Music underwater has a really strange sound, because you're hearing it through your whole body and your head and your jaw," said festival coordinator Bill Becker. "It travels five times faster than it does in air, so it reaches your ears and your head at exactly the same time."
Some participating divers costumed themselves as the "Rolling Stone Crabs" and "played" instruments underwater to salute the Rolling Stones' 50th anniversary,
The name referenced both the legendary rock band and the stone crabs inhabiting Keys waters, whose claws are a renewable seafood resource.
The broadcast's playlist included Stones' classics and ocean-themed tunes such as the Beatles' "Octopus's Garden" and Jimmy Buffett's "Fins."
Snorkeler Candy Mausser, of Sarasota, said she thought the fish were enjoying the unaccustomed concert.
"There were about 100 angelfish and they were all going back and forth underwater with the music," Mausser said.
The broadcast also emphasized reef preservation with diver awareness tips on enjoying the ocean while minimizing impacts on the marine environment.