The Lower Florida Keys’ sub-sea world will become a one-of-a-kind concert venue Saturday, July 13, when divers and snorkelers immerse themselves in a musical adventure that promotes reef protection.

Lower Keys Underwater Music Festival mermaids

“Mermaids” join the fun to support the message of coral reef conservation at at a past Lower Keys Underwater Music Festival. (Photo by Mike Papish, Florida Keys News Bureau)

It’s called the Lower Keys Underwater Music Festival, and it’s unlike any other dive or snorkel experience — OR any other music festival — to be found on the planet.

The submerged songfest takes place each year about 6 miles south of Big Pine Key at Looe Key Reef, well known as one of the most extraordinary areas in the Florida Keys National Marine Sanctuary. Established in 1990, the sanctuary is an eco-treasure that protects the waters surrounding the entire Keys island chain — including the continental United States’ only coral barrier reef.

And the concert? Created to encourage coral reef preservation and environmentally responsible diving, it’s presented each year by the Lower Keys Chamber of Commerce and coordinated by Keys radio station US1 104.1 FM.

Now in its landmark 40th year, the marine-themed music fest has been going strong since the 1980s. And attendees agree that it makes the already amazing Florida Keys underwater experience even better.

Each year, the incomparable concert draws several hundred divers and snorkelers to enjoy the sound of music while discovering (or rediscovering) the Lower Keys’ ocean realm.

Looe Key Reef Florida Keys

Looe Key Reef, a part of the Florida Keys National Marine Sanctuary, is widely regarded as a remarkable dive experience.

Festival events begin Friday, July 12, with a free 6-8 p.m. welcome gathering at Mote Marine Laboratory’s Elizabeth Moore International Center for Coral Reef Research & Restoration on Summerland Key. Attendees can tour the facility and learn about Mote’s groundbreaking coral cultivation and restoration efforts.

Saturday morning, participants will grab their gear and board boats heading for Looe Key Reef.

How does the “music” part of the festival work? For four hours, tunes broadcast by the radio station are piped underwater via special speakers suspended beneath boats above the reef — providing a distinctive “soundtrack” for everyone enjoying the unique adventure.

Swimming among colorful tropical fish and coral formations, divers and snorkelers can listen to sea-focused offerings that typically range from Jimmy Buffett’s “A Pirate Looks at 40” and “Fins” to the Beatles’ “Octopus’s Garden” and the theme from “The Little Mermaid” film.

In fact, as in past festivals, participants are likely to spot mermaids — or at least divers dressed as the mythical lovelies — beneath the waves. Sometimes joined by other costumed characters, they add a lighthearted visual component to the concert as they “play” musical instruments in a rollicking oceanic jam session.

Costumed divers Underwater Music Festival

A yellowtail snapper swims by participants pretending to play instruments sculpted by local artist August Powers at a previous Lower Keys Underwater Music Festival. (Photo by Bob Care, Florida Keys News Bureau)

The Lower Keys Underwater Music Festival offers an undeniable bucket-list experience, but even more important is its focus on environmentally conscious diving.

Aquatic enthusiasts will receive valuable insights into preserving and protecting the world’s coral reefs, whose rich biodiversity has led them to be called the rainforests of the sea.

Diver awareness messages will be played throughout the broadcast, stressing elements like the importance of not touching corals or leaving litter underwater, using mooring buoys instead of anchoring when boating, respecting dive flags, and other ways of minimizing environmental impacts while exploring the reef.

And by the way, it’s not just divers and snorkelers who appreciate the marine melodies. According to past fest-goers, even fish on the reef tend to react positively — seemingly swaying to the music as they swim.