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Deep blue: Where to dive in blue holes around the world

By Oliver Pearson   Last Updated: 23 March 2023

A breathtaking sight from above and equally impressive below the surface, blue holes are natural phenomena that are best experienced by scuba pros. Discover the best spots to dive in blue holes as part of a luxury yacht charter

What is a blue hole?

A relic of the Ice Age, blue holes are intriguing geological formations that were formed after rising water levels filled existing sinkholes. Deep and cavernous, the water in these holes takes on a dark navy shade that’s ultimately come to define them.

The blue holes found around the world are filled to the brim with exotic wildlife as well as underwater flora and fauna that make them fascinating sites for marine research and present a fantastic diving opportunity during a yacht charter vacation.

Blue hole diving spot

Blue holes are reserved for seasoned and confident divers.

Whilst diving in a blue hole makes for an unforgettable experience, it’s one that’s reserved for seasoned and confident divers. Classified as a ‘technical dive’, exploring the likes of the Belize Hole requires divers to possess excellent buoyancy control and the ability to equalize with ease.

It’s crucial that when diving in a blue hole, divers maintain a close eye on their air consumption, depth, and time underwater. They also need to be aware of any tourist board regulations that they’ll need to abide by whilst exploring.

For the above reasons, it’s strongly recommended that when diving in a blue hole, you seek out a reputable dive centre who can provide you with a qualified divemaster to accompany you on your excursion.

Are blue holes dangerous?

Scuba diver swims through blue hole

Blue holes are no more dangerous than any other technically challenging dive site. Providing the correct safety measures are carried out, and all regulations are abided by, divers are able to securely navigate the remarkable underwater formations with very little risk.

Certified divemasters will also be able to help parties avoid any sharks or wildlife that could pose a potential threat in a blue hole.

What's at the bottom of a blue hole?

Blue hole from above, sandy beaches in background

In 2018, a historic research project was launched to find out what’s at the bottom of Belize’s Blue Hole. Hosting marine conservationists, environmental scientists, and Virgin founder Richard Branson, a submarine headed down 300ft to take a first look at the ocean bed.

What they found was astonishing.

A wall of stalactites revealed that the Blue Hole is in fact made up of caves that were originally on land before ocean waters started to rise. Demonstrating how radically the earth has transformed over 10,000 years, changes in the rocks as this depth show how the area has transitioned from land to sea over time.

Fish in blue hole in blue holes
Diver swims below stalactites in blue holeBlue hole with big ugly fish in the deep water

Due to the lack of oxygen at the bottom of the blue hole, no marine life exists that far down; however, there are countless fish species that exist at different depths. 

How deep are blue holes?

The blue holes found around the world are each made up of individual characteristics and have varying depths.

The following are the depths of popular blue holes:

  • Dean’s Blue Hole (633ft deep)
  • The Belize Blue Hole (407ft deep)
  • Dahab Blue Hole (328ft deep)
  • Dwejra Blue Hole (49ft deep) 

The deepest is the Dragon Hole in the South China Sea. Otherwise known as ‘Longdog’, this hole is 987 feet and is naturally a source of fascination to the scientific and diving community.

The deepest blue hole in the world, Dragon Hole in the South China Sea

The best blue holes for diving:

The Great Blue Hole, Belize

Unquestionably the most iconic and most photographed blue hole of them all, the blue hole in Belize is a veritable wonderland for divers. Coined “The Great Blue Hole” by British author Ned Middleton after he likened its grandeur to Australia’s Great Barrier Reef, its large, 1,000-foot wide entrance, can be found at the center of the colorful Lighthouse Reef.

Put on the map by acclaimed French explorer Jacques Cousteau after he declared it one of the top five scuba diving spots in 1971, the hole is home to nurse sharks, butterfly and midnight fish as well as turtles and groupers.

Comprised of enormous stalactites, columns, and dripstone sheets, there’s certainly plenty of dramatic sights for underwater adventurers to discover.

One of the seven wonders of Belize’s World Heritage site, a diving expedition at the Belize Blue Hole is essential for any qualified diver planning a yacht charter vacation in the Caribbean.

Dean's Blue Hole, the Bahamas

Located a short distance from the coast of Clarence Town in the Bahamas, Dean’s Blue Hole is the world’s second deepest blue hole. With a diameter that reaches around 100m, the hole boasts incredible visibility which makes it easy to spot tarpons, turtles and an assortment of other marine life that call the hole home.

The hole boasts incredible visibility

Formed by eroding and dissolving limestone, the vast cavern which defines the blue hole is the ideal spot for an advanced diving expedition.

A paradise for enthusiasts, Dean’s Blue Hole is also the site of an annual freediving competition hosted by world champion William Trubridge. There is, however, no need to compete in order to enjoy the delights of this particular spot.

The Red Sea Blue Hole, near Egypt

Situated a few kilometers north of Dahab, the Red Sea Blue Hole is the perfect spot for experienced divers enjoying a yacht charter vacation in Egypt. Accessed via a shallow opening termed “the saddle” around 20ft deep, the formation is decorated with vibrant coral and populated by tropical reef fish.

Scuba diver in distance of blue hole in Egypt
Red Sea blue hole, birds eye shot
Blue Hole as seen from underwater

With a distinct lack of current and easily reached from the shore, the Red Sea Blue Hole is just as popular amongst freedivers as it is professionals. Whilst the more experienced diver is certain to get more out of its depths, there’s certainly enough to be enjoyed by the casual snorkeler keen to take a look beneath the water.

It should be pointed out that the Red Sea Blue Hole is among the more dangerous blue holes for diving due to its formation being somewhat deceptive. In order to experience it safely, always follow the advice of a qualified divemaster.

Malta's Blue Hole

Located beneath the sublime Azure Window, the Blue Hole of Malta - otherwise known as the Dwejra Blue Hole- is far shallower than those found elsewhere around the globe. Whilst 49ft is certainly a suitable depth for a scuba dive, it’s certainly less intimidating than the blue holes found in Belize or Dahab. 

Despite its relatively small size, this blue hole is still buzzing with marine life. Specifically, it’s home to octopi, seahorses, fireworms, as well as various species native to Malta. Its layout also lends itself to adventure, with the inner cavern being accessed via a 262-foot tunnel that’s easily navigable thanks to the clear visibility the hole benefits from. 

The dramatic rock structure which towers above it is also worth noting - it’s a landmark that’s been used in countless motion pictures and even made its way into an episode of Game of Thrones.

Whichever blue hole you decide to check out on your next yacht charter vacation, be sure to get in touch with a licensed dive center to ensure that you visit it safely. Speak to your preferred yacht charter broker for more information on how to incorporate a divemaster into your yacht charter.

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