7 Underwater Volcanoes Perfect for Scuba Diving
A volcano is any mountain that contains a vent into the planet’s crust, through which lava, rock, gas or ash can erupt. Many islands and underwater formations are formed by volcanic activity, and they're often hot spots for great diving.
Dark volcanic substrate contrasts with the brilliant colors of the reef off Barren Island.
Mark Strickland
Barren Island
Andaman Islands
Beneath the clear blue water around this active volcano in the Andaman Sea are vibrant, coral-laced walls alongside fields of black volcanic sand and freshly formed lava rock. The island rises from the open ocean, topped by a smoldering volcano and ringed by dramatic formations. Divers can explore a lava rock cavern at the dive site Purple Haze, while Manta Point has a current-swept precipice that hosts cleaning stations for traveling manta rays. Liveaboards to Barren Island operate from Port Blair on South Andaman Island.
Batu Tara Volcano
Indonesia
Motoring to the remote Komba Island, in Indonesia’s newest frontier of diving east of Flores Island, intrepid divers can witness the smoke and pyrotechnic displays of Batu Tara, a stratovolcano that has frequent bursts of geothermal activity. These topside displays are mesmerizing, but the view underwater is equally stunning, with profusions of soft corals, schools of fish such as barracuda and dogtooth tuna, and a healthy collection of macro critters. The region is renowned for oddities like frogfish, mimic octopuses and seahorses hidden among brilliantly colored fans and soft corals.
Komba’s volcano towers over the waters of Indonesia’s Flores Sea.
Renee Capozzola
Mahengetang Banua Wuhu
Indonesia
For a truly special — and unusual — diving experience, look to Indonesia’s Banua Wuhu, off Mahengetang Island near North Sulawesi. Unlike many other volcano dive sites, Banua Wuhu lies completely underwater, with its sulphur-covered peak rising to about 20 feet below the surface. The rocky substrate bubbles with the gases released by geothermal activity below, and the water temperature hovers at roughly 100 degrees around the volcano, creating an experience akin to scuba diving in warm Champagne.
Molokini Crater
Maui
One of the most popular diving and snorkeling spots in Hawaii is the volcanic cinder cone off South Maui called Molokini. This crater was created by the same hot spot that formed the island of Maui. Over the eons since it was formed, the north side of the crater eroded, leaving a crescent-shaped island that nurtures shallow reefs on the inside, and a dramatic 300-foot submarine wall on the backside. These shallow reefs are filled with fish such as the endemic banded angelfish. The back wall offers opportunities to spot pelagics, such as manta rays and humpback whales, cruising the Alalakeiki Channel.
READ MORE: 6 Awesome Atolls for Scuba Diving
A colorful porcelain crab perches on an anemone off Garove Island.
Doug Perrine
Garove Island
Papua New Guinea
In Papua New Guinea’s Vitu Islands, a collection of volcanic peaks north of New Britain, liveaboard boats can sail into the caldera of Garove Island’s volcano, a near-perfect circle at the heart of the island that is nearly 1,000 feet underwater at its center. The black volcanic-sand seafloor inside the caldera makes it one of PNG’s legendary spots for muck diving. Underwater photographers scour these sandy sites looking for alienlike critters, from leaf scorpionfish to blue-ribbon eels. Dive sites like Dicky’s Place offer long bottom times and enough surprises for multiple dives, especially at night when a new cast of critters emerges.
Gordon Rocks
Galapagos
The Galapagos Islands were formed by volcanoes, and the famed Gordon Rocks dive site was a volcanic cone that arose to the east of Santa Cruz Island, its caldera eroding away with eons of wind and wave action. Today, you can make out a faint crescent shape from the air, but at boat level it looks like three rocks protruding from the water. The channel between the north and south rocks passes over the caldera, creating a shallow area with heavy surge. Around the edges, the seamount drops into the depths. It’s here you’ll find the star attraction: massive schools of hammerhead sharks sweeping across the blue backdrop like squadrons of fighter jets. It’s also a good spot for rays, Galapagos sharks and schooling barracuda.
Superman’s Flight
St. Lucia
Enjoy a powerful drift dive in the shadow of one of the Caribbean’s most iconic volcanoes. Superman’s Flight lies just offshore at the base of Petit Piton. The sloping wall is the underwater extension of the volcano’s flank, extending more than 1,000 feet underwater. Situated at the westernmost point of the mountain, the site is buffeted by strong currents, giving divers a thrilling ride as they sweep past immense barrel sponges and filter-feeding corals.