The continental United States’ only contiguous living coral barrier reef, which parallels the Florida Keys, hosts huge populations of tropical fish and other creatures. Purple gorgonians, giant boulder corals, elegant finger corals, colorful shrimp, shy and skittish lobsters, bashful nurse sharks and rays provide an incomparable display of undersea life to divers and snorkelers.

divers in Underwater Pumpkin Carving Key Largo

Sophie Costa (left) and Allison Candelmo display their completed entry in a previous Underwater Pumpkin Carving Contest. (Photo by Frazier Nivens, Florida Keys News Bureau)

The Keys reef is easy to get to and easy to navigate, while the warm clear water makes a long dive comfortable and enjoyable.

Around Halloween, however, the region’s underwater beauty goes hand in hand with offbeat fun.

That’s because Halloween in the Keys brings a popular yet unusual event: the Underwater Pumpkin Carving Contest (yes, involving actual pumpkins) in Key Largo waters. (Key Largo, by the way, is the northernmost part of the island chain and is renowned as the Dive Capital of the World.)

Set for Saturday, Oct. 29, the contest is now in its 24th year and features intrepid “artists” descending approximately 25 feet beneath the surface. Their task: transform orange pumpkins into masterful sculptures incorporating frightening facial features, playful denizens of the sea or traditional toothy grins.

As well as design challenges, participants must contend with two other elements. First, hollow pumpkins are naturally buoyant. In other words, they tend to float — which means subsea sculptors must work with a potentially moving target AND keep it from drifting away.

Second, as seasoned pumpkin carvers know, hollowing out the gourds’ interior reveals seeds and stringy “guts.” These float too, and often attract quick-swimming reef fish that move in for a closer look and a nibble on the intriguing tidbits — so dodging finned “spectators” becomes part of the artistic process.

Underwater Pumpkin Carving Key Largo

Divers finish paring their Halloween creations in a recent Underwater Pumpkin Carving Contest held in Key Largo waters. (Photo by Mike Papish, Florida Keys News Bureau)

Each year, however, the pumpkin carvers not only persevere but report having a great time — competing to craft the most innovative creations to win prizes and bragging rights.

Previous years’ pumpkin entries have featured everything from traditional triangle eyes and toothless grins to shark-mouthed sneers, dolphin silhouettes and many other sea creatures. One crafty past competitor even came up with a “fishy” skeleton.

Certified divers can join in the Oct. 29 competition with Amoray Dive Resort, located at mile marker 104.5 in Key Largo. The two-location dive includes tanks, weights and a pumpkin ready for carving. Reservations are an absolute MUST.

Once the carving is complete, the top pumpkin chosen by the experienced judges (who double as the crew of the Amoray Diver dive boat) earns its creator a complimentary dive trip for two.

If you’re an advanced- or wreck-certified diver, Key Largo waters also offer another one-of-a-kind underwater adventure: the chance to dive on the 510-foot U.S. Navy ship Spiegel Grove, the world’s third-largest ship ever intentionally sunk to become an artificial reef. The vessel has enthralled trained divers since June 2002, when the Key Largo community rallied to sink it as the backbone of a new reef ecosystem.

Lisa Mongelia swims between gun turrets of the Spiegel Grove, sunk in 2002 six miles off Key Largo to become an artificial reef. (Photo by Frazier Nivens, Florida Keys News Bureau)

Designed to carry cargo and craft for amphibious landings, the Spiegel Grove operated from 1956 until its decommissioning in 1989, and helped enforce America’s Cold War strategy by rushing troops and equipment to support friendly governments.

Today, the venerable vessel rests in 130 feet of water about six miles off Key Largo. Enveloped by delicate corals and invertebrates, the top deck is about 60 feet below the ocean’s surface.

The ship is so wide that, on many days, the view of the superstructure will fade into a green-blue abyss. On the clearest days, however, the sandy bottom is visible.

For wreck divers who intend to enter the upper deck areas of the Spiegel Grove (which were specially prepared to lessen the risk of such activity), knowledge and proof of certifications regarding diving in overhead environments is required.

Whether you’re coming to the Florida Keys to carve a pumpkin underwater, explore a unique reef ecosystem or embark upon an only-in-the-Keys shipwreck dive, you’ll find plenty of professional dive operators to help you immerse yourself in the underwater realm. For more information, just click here.