BIG PINE KEY (CBSMiami/FKNB) – A music festival in the Keys, all in the name of a good cause, had about 200 people, and perhaps sea life, swimming to tunes heard underwater via waterproof speakers on Saturday.

The 29th annual Underwater Music Festival, which had “divers dancing” according to the festival’s coordinator Bill Becker, took place at Looe Key Reef, about six miles south of Big Pine Key.

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Daron Erznoznik blows into a sculptor's rendition of a saxophone at the Lower Keys Underwater Music Festival Saturday, July 13, 2013, in the Florida Keys National Marine Sanctuary off Big Pine Key, Fla. About 200 snorkelers and divers gathered to listen to a local radio station's broadcast that was piped beneath the sea.  (Bob Care/Florida Keys News Bureau/HO)

Daron Erznoznik blows into a sculptor’s rendition of a saxophone at the Lower Keys Underwater Music Festival Saturday, July 13, 2013, in the Florida Keys National Marine Sanctuary off Big Pine Key, Fla. About 200 snorkelers and divers gathered to listen to a local radio station’s broadcast that was piped beneath the sea. (Bob Care/Florida Keys News Bureau/HO)

Keys radio station WWUS 104.1 FM hosts the event where four hours of music will be broadcasted via waterproof speakers below boats floating above the living coral barrier reef.

Hundreds of divers and snorkelers are expected to attend the underwater festival. Some participating divers, in honor of the 50-year-career of famed rock group the Rolling Stones, will costume themselves as “The Rolling Stones Crabs.”

The Stones-costumed divers “performed” with underwater instruments sculpted by a local artist.

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“Music underwater has a really strange sound, strange feeling, because you’re not hearing it through your ears,” said Becker. “You’re hearing it through your whole body and through your head and your jaw.”

Candy Mausser, a snorkeler from Sarasota, FL, believes the sea life may have actually have enjoyed the festival.

“I do think the fish were enjoying it too,” Mausser said. “There were about 100 angelfish and they were all kind of going back and forth underwater with the music.”

Grooving to tunes underwater, while fun, has a serious message—promoting the preservation of the continental United States’ only living coral barrier reef.

During the broadcast, featuring nautical-inspired tunes like Beatles “Octopus’s Garden” and Jimmy Buffett’s “Fins,” public service announcements were played emphasizing ways to enjoy the reef while minimizing environmental impacts.

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“The Florida Keys News Bureau contributed to this report.”