In April 2008, a handful of freedivers dove into a marine abyss south of Long Island in the Bahamas and broke three world records and twenty-three national records over ten days of competition. Since that first event, Dean’s Blue Hole, near Clarence Town, has established itself as one of the world’s premier venues for constant-weight freediving.
This sinkhole owes its fame to a specific figure—202 meters below the surface—which was scientifically measured as early as 1994. Long touted as the world’s deepest marine blue hole, it now ranks third in the world, according to the Bahamian tourism authorities themselves—a ranking that few destinations publicize so openly.
Dean's Blue Hole, a bell-shaped sinkhole near Clarence Town
Long Island stretches about 130 kilometers, is barely 6 kilometers at its widest point, and has fewer than 3,000 residents. Clarence Town, its administrative capital, is home to only about a hundred of them, scattered among a few stone buildings dating from the post-slavery era and two churches built by the same priest-architect in the early twentieth century.
Just a few minutes away lies Dean’s Blue Hole, a narrow entrance in the limestone that suddenly widens underwater into a bell-shaped chamber. Researcher William Wilson published the first precise scientific measurement of its depth in 1994 in the Bahamas Journal of Science: 202 meters deep. The porous limestone that makes up the entire Bahamas explains the exceptional concentration of marine sinkholes of this type in the archipelago—a phenomenon rarely seen elsewhere in the world.
202 meters that have made Long Island a global hub for freediving
Calm, current-free water and sufficient depth just a few meters from the shore—these are exactly the conditions sought by constant-weight freediving, a discipline in which the athlete descends and ascends using only their own body strength, without assistance. Dean’s Blue Hole meets these conditions better than any other site accessible from the shore.
That is what led freediver William Trubridge to found the Vertical Blue competition there in 2008. Open only to invited athletes, it has since been the site of several world records, including one set by British athlete Sara Campbell in 2009. Every year, the small global community of competitive freedivers returns to this stretch of Long Island, transforming a fishing village into an event closely followed by the sport’s international federations.
In July 2025, the fifteenth edition of Vertical Blue once again broke that record. France’s Arnaud Jerald set a new world record in the constant-weight, bi-fin category at 126 meters, while Slovenia’s Alenka Artnik tied the women’s best performance in the discipline at 123 meters. Seventeen years after its inception, Dean’s Blue Hole continues, every summer, to push the limits of the human body in freediving a little further.
Ranked third in the world—a distinction few destinations can claim
For decades, Dean’s Blue Hole was cited in guidebooks and news reports as the world’s deepest marine blue hole. That is no longer the case. The Dragon Hole, in the South China Sea, surpasses it at approximately 301 meters. And a study published in 2024 in the journal *Frontiers in Marine Science* measured Taam Ja’, in Chetumal Bay, Mexico, at more than 420 meters, though researchers have not yet reached the bottom.
Rather than continuing to claim a record that has been surpassed, the official Bahamian tourism website now lists Dean’s Blue Hole as the third-deepest marine blue hole in the world. This level of precision—rare in an industry that often favors hyperbole over accuracy—speaks volumes about the site itself; its value lies not in a ranking, but in what freedivers and scientists continue to discover there.
Long Island, a protected area that attracts freedivers from around the world every year
The limestone of the Bahamas is home to the highest concentration of marine sinkholes in the world, a geological treasure documented by the Bahamas National Trust, the national conservation organization. Many of these blue holes, including Dean’s Blue Hole, remain fragile ecosystems that are sensitive to runoff and human activities near the shoreline.
Long Island, on the other hand, has retained an economy centered on fishing and small-scale agriculture, far from the large hotel resorts found on other Bahamian islands. Every new measurement of a marine abyss elsewhere in the world could still reshape this ranking of the deepest points. In Clarence Town, this does not change what freedivers come to seek each year in the calm waters of Dean’s Blue Hole.
Dean’s Blue Hole reaches a depth of 202 meters below the surface, a measurement established by researcher William Wilson in 1994 in the Bahamas Journal of Science. The blue hole opens with a narrow entrance that suddenly widens underwater into a vast, bell-shaped chamber.
No, it currently ranks third in the world. Dragon Hole, in the South China Sea, is about 301 meters deep, and Taam Ja’, in Mexico, was measured at more than 420 meters in a study published in 2024.
Dean’s Blue Hole is located on Long Island in the Bahamas, near Clarence Town, the island’s administrative capital.
