BIG PINE KEY, Fla. (AP) — A local radio station's broadcast underwater in the Florida Keys National Marine Sanctuary on Saturday attracted about 400 divers and snorkelers who listened to music and announcements advocating reef preservation.

The Lower Keys Underwater Music Festival at Looe Key Reef, part of the world's third-largest living coral barrier reef, featured four hours of music custom-programmed by station WWUS for subsea listening.

"We have a captive audience down there," said Bill Becker, the event's co-founder and the station's news director. "We have divers and snorkelers listenin...