Ocean Sinkholes Around the World

Sinkholes terrify us—on land, they damage everything in their paths and threaten the lives of locals. But out at sea, sinkholes, known as blue holes, are more mysterious and exciting. Divers risk their lives to see what’s within the depths of these ocean sinkholes around the world.

Dragon Hole

Located in the South China Sea (Near the Paracel Islands)

The Dragon Hole was discovered in 2015, with diving explorations of the site lasting well into the following year. Measuring 426 feet wide and with a depth of about 987 feet below the ocean’s surface, it is the deepest known underwater sinkhole in the world. The Dragon Hole is also known by the locals as the “eye” of the South China Sea, where the Monkey King found his famed golden cudgel in the Chinese mythical classic “Journey to the West.”

Dean’s Blue Hole

Located in the Bahamas

The former deepest underwater sinkhole before the discovery of the Dragon Hole, this blue hole is approximately 663 feet deep. After a descent of about 66 feet, the cavern diameter, averaging 98.5 feet, widens into a large, open cave that continues downward into the Earth. Because of the sinkhole’s close proximity to Long Island, professional divers often frequent the area to test their skills in the sport. Diving from the cliffside, they attempt to break the world record depth set by William Trubridge in 2010 with a dive of 331 feet.

The Great Blue Hole

Located off the coast of Belize

What this sinkhole lacks in depth it makes up for in sheer size. Spanning just as wide as the Dragon Hole is deep, the Great Blue Hole is believed to have originally formed from a limestone cave that was flooded and collapsed as the sea levels began to rise. This is another site that is popular with divers, as the waters are clear enough to see the beautiful rock formations and possible wildlife in the right seasons. One diver in particular, Jacques Cousteau, made the site famous when he declared it to be one of the top ten best diving places in the world in 1971.

Red Sea Blue Hole

Located on the East Coast of the Sinai Peninsula

While these sinkholes might seem like every free diver’s dream, there’s one blue hole that has become their nightmare. Nicknamed the “Diver’s Cemetery,” this blue hole is notorious for being fatal to any divers who try to brave its depths. It is estimated that at least 40 divers have died in these waters, though some think the number is much larger. But despite this deadly reputation, the sinkhole has proved to be appealing to divers wishing to test their limits, as it still has frequent visitors.

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Written by Logan Voss

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