It’s February 2019, and a team of researchers are busy studying Darvel Bay off the island of Borneo in Malaysia. But as they explore the sparkling blue waters of the South China Sea, they discover that something incredible has been hiding beneath the waves. In fact, it’s a unique anomaly unlike anything that has been seen before.
Today, experts have catalogued a number of blue holes scattered throughout the oceans of our world – mysterious dark voids that stand in stark contrast to the lighter shallows around them. They are deep caverns that formed thousands of years ago, only to be swallowed by rising tides. But for modern explorers, they hold an almost mystical appeal that’s hard to beat.
Popular with everyone from boat trippers to scuba divers, blue holes provide an incredible opportunity to gaze into the wonders of the deep. And from the 400-foot chasm that penetrates Lighthouse Reef in Belize to the record-breaking sinkhole located off the coast of the Paracel Islands, they form some of the most impressive spectacles on planet Earth.
In fact, each year sees hundreds of thousands of curious visitors make pilgrimages to sites like the Great Blue Hole. However, not all of our planet’s underwater caverns have found their way into the tourist brochures over the years. And sometimes, a lucky diver can hit the jackpot by total chance.
According to experts, the world’s blue holes were first created during the ice ages. At the time, sea levels across the planet were as much as 390 feet below what they are today. And so, the structures that are now underwater were once exposed to fresh air – and the same erosion processes that typically affect dry land.
In places, pliable limestone rock was exposed to weathering – both from the rain and from chemicals in the atmosphere. As a result, caverns in the landscape began to appear. And when the sea levels rose to submerge them, they became the blue holes known and loved by divers around the world.
Today, blue holes appear as vast underwater chasms that stretch deep below sea level. And because there is little oxygen down in the depths, they are often spookily devoid of any life. However, their mesmerizing, dark blue waters draw countless visitors who get a kick out of peering down into the murky abyss.
Perhaps the most well-known example of this phenomenon is the Great Blue Hole. This giant, circular chasm is located some 40 miles off the coast of Belize. In fact, it has actually been famous since around 1971, when the explorer Jacques Cousteau arrived in his research vessel Calypso to document its depths.
Today, the Great Blue Hole is recognized as one of the best scuba diving locations on the planet. And in 1997 a team of experienced explorers were finally able to reach the bottom of the chasm – located more than 400 feet beneath the waves. However, this pales in comparison to the terrifying size of the deepest blue hole in the world.
Currently, that honor goes to Dragon Hole, a chasm that stretches for almost 990 feet beneath the surface of the South China Sea. Located in the Paracel Islands approximately halfway between China and Vietnam, this impressive blue hole has been dubbed the “eye” by reverent locals. In fact, some believe that it is linked to the legend of the Monkey King – a centuries-old character from classic Chinese literature.
Because of its remote location, Dragon Hole has remained relatively unexplored by divers over the years. However, the same cannot be said for Dean’s Blue Hole, a roughly 663-foot cavern located off the coast of Long Island in the Bahamas. In fact, this site is so popular that it plays host to an annual free-diving competition known as Vertical Blue.
Amazingly, these aren’t the only blue holes that punctuate the sparkling surface of the world’s oceans. Just off the remote Pacific island of Guam, for example, an underwater cave with a heart-shaped entrance draws divers from around the world. Elsewhere, in 2019 scientists announced that they’d found a deep chasm beneath Australia’s Great Barrier Reef.
Meanwhile, thousands of miles away in Egypt, the Red Sea’s Blue Hole has developed a reputation as the deadliest diving site in the world. Located off the Sinai Peninsula near the town of Dahab, this underwater cavern stretches for some 330 feet beneath the surface. Additionally, it also boasts an 85-foot tunnel connecting it with the open ocean beyond.
In their attempts to reach this tunnel, however, numerous divers have lost their lives. In fact, it’s been suggested that as many as 200 people have died at Egypt’s Blue Hole in recent years. Famously, this statistic includes the Russian instructor Yuri Lipski, whose chilling final moments were captured on video and watched by millions online.
But despite the many deaths associated with them, blue holes continue to inspire divers and explorers around the world. Which is why much excitement was generated back in March 2019, when a team of researchers announced the discovery of a new underwater cavern. And like the famous Dragon Hole, this one was also located in the South China Sea.
In February 2019 representatives from the Malaysian conservation group Sabah Parks, or TTS, joined divers on an expedition off the eastern coast of Borneo. Apparently, the aim of the mission was to collect information about aquatic life in a region known as Darvel Bay. However, they ended up finding something else entirely.
According to initial reports, the team stumbled across something strange while using remote sensing technology to scan the bay. Apparently, they picked up an anomaly which they believed to be coral at first, before realizing the true extent of their find. Amazingly, they had managed to uncover a rare blue hole.
While most blue holes consist of a single chasm, the one in Darvel Bay is made up of two distinct structures – making the discovery even more unique. And according to the team, each cavern stretches for around 50 feet beneath the surface. Nevertheless, divers from the expedition were able to thoroughly explore its incredible depths.
“We explored both blue holes and could cover the site with just one tank of gas,” Nasrulhakim Maidin, a senior research officer with TTS, told the New Straits Times in March 2019. “The experience was amazing. When we came out of the blue hole from the left to the right, we were like moving over a mountain range in the sea.”
At between 165 and 230 feet across, the Darvel Bay blue holes are a relatively small example of this phenomenon. However, their accessibility – just a 20-minute boat ride from the mainland – could prove a major draw for divers. Indeed, there’s hope that this unknown corner of Borneo could be transformed into a prominent spot for tourists in the wake of the discovery.
“If this sunken coral structure (like a cave in water) is promoted as a diving site, it could become a major tourist attraction such as the Great Blue Hole of Belize (Central America), Blue Hole Dean (Bahamas) and the Dragon Blue Hole (China),” Maidin continued. However, he went on to claim that the entire region of Darvel Bay should be protected before any development takes place.
Apparently, Darvel Bay covers some 247,105 acres of ocean and comprises around 50 islands. And according to experts, it’s not just tourists that could be drawn to the area and its striking blue hole. In fact, it’s believed that the abundant corals in the region could also attract endangered turtles looking for a favorable habitat.
But while Borneo’s officials celebrated their good fortune, there came another twist in the tale. On March 12, 2019, it was revealed that one local diver had known about the blue holes for years before their discovery had been officially announced. Apparently, Glen Hapirulla had been exploring the site since at least 2017.
According to Hapirulla, who runs a company called Lahad Datu Pirate Divers, his team first stumbled upon the anomaly while scouting for new locations in the region. And as well as mapping and cataloging their find, they gave it a name – Blue Rings Reef. However, Hapirulla did not believe that the caverns were truly blue holes at first.
Apparently, blue holes are typically circular in appearance – and the Darvel Bay site does not meet this criterion. “This dive site is not interconnected, but instead each is a different large hole,” Hapirulla told the Borneo Post in March 2019. Nevertheless, he had been taking divers to explore the location for two years before the team from TTS claimed to have discovered it.
At first, some members of the diving community went online to blame TTS for taking credit for Hapirulla’s discovery. However, the organization strongly denied such claims. In fact, Jamili Nais, the director of TTS, told the press that they had wanted the veteran local diver involved in their expedition from the start.
“We wanted to correct any misconception that we are stealing credit from Glen, who has been diving there for nine years and brought people to these blue holes in the last two years,” Nais told a news conference in March 2019. “We would like to congratulate him and apologize for any inconvenience. It was not our intention to take credit for his discovery.”
“We had actually launched a scientific expedition to the area with University Malaysia Sabah and Sabah Foundation,” Nais continued. “[We] invited Glen but he was away at the time in Singapore and couldn’t join us. And it was during the expedition that we came to know about the blue holes.”
As well as apologizing to Hapirulla, Nais also echoed calls for conservation alongside tourist development in Darvel Bay. In fact, he noted that corals in the region had been damaged since at least the 1990s. “30 years later the conditions are still bad,” he explained. “But if we gazette it now, it can be rehabilitated for the future generation.”
Meanwhile, Hapirulla confirmed that the discovery was initially his – although he graciously accepted Nais’ apology. “I’ve been diving there for years but I first realized it was a blue hole when we flew a drone over the area,” he explained in an interview with the Malay Mail. “I posted it on Facebook but it did not garner a lot of attention until now.”
Hapirulla hopes to work alongside the local authorities to develop the Darvel Bay site to benefit the local community. And while conservation remains a priority, many are keen to promote the blue hole as the latest must-see diving attraction. After all, it could ultimately flourish into a draw on a par with those in the Bahamas and Belize.
For the impoverished state of Sabah, where Darvel Bay is located, such an attraction could prove to be a welcome source of income. In 2018 the region earned the equivalent of almost $1.9 billion in tourist revenue – largely thanks to Semporna’s beautiful Sipadan Island. In fact, this stunning location is generally regarded as one of the best places to dive in the entire world.
And now a blue hole has been discovered in the area, conveniently located close to existing developments on Sipadan. So Sabah’s popularity as a diving destination looks set to grow. In fact, it seems only a matter of time before explorers start making their way to this fascinating spot in the South China Sea.
But those keen on diving in Darvel Bay would do well to remember that blue holes hide many dangers. Just a few months before TTS announced their discovery, for example, the bodies of two divers were spotted at the bottom of the Great Blue Hole in Belize. Apparently, a number of people have disappeared while exploring the cavern over the years.
In December 2018 Canadian company Aquatica Submarines visited the Great Blue Hole. Here, they used a submersible to map the interior of the underwater cavern. But when they descended below 290 feet, they discovered an atmosphere devoid of oxygen. “Anything that falls down there now is preserved,” the expedition’s Erika Bergman told Newsweek in February 2019.
“Without oxygen, nothing survives,” Bergman continued. “Beneath the hydrogen sulfide layer it is very dark. Looking straight up from inside the submarine you can just barely make out the circular opening of the hole, all of the light pouring into the hole is shut out by the thick chemical layer.”
As the submarine descended into this lifeless abyss, the team spotted some strange tracks crossing the ocean floor – the origin of which remains unknown. And movingly, they also discovered the remains of two divers. “We notified the local authorities, and everyone agreed to leave them undisturbed,” Bergman explained. “They are at peace.”
Meanwhile, over in Egypt, people continue to perish in the Red Sea’s Blue Hole at an alarming rate. In fact, local diver Tarek Omar estimates that he has removed over 20 bodies from the cavern since 1997. Additionally, the popularity of free-diving at the site has added to its danger.
According to some, the deaths here are not just the result of challenging conditions. In fact, local legend tells of a curse on the hole, laid by a woman who chose a watery death rather than face an arranged marriage. However, Omar believes that the reality is far more prosaic. “The people who dive here have created their own curse,” he told the Guardian in 2017.
Back in Malaysia, authorities are no doubt hoping that the deadly trend will not extend to their own blue hole. But for now at least, the discovery remains a source of excitement and hope for the region. And of course, it’s an irresistible challenge for adventurers from around the world.