Serene turquoise surface Caribbean Sea suddenly ends in sharp dark blue blackness. The water suddenly becomes surprisingly dark, and it seems as if great amount For some reason, the octopuses gathered here, and then, scared of something, they simultaneously released their ink. After this, the colored water was enclosed in a circle of incredible beauty by coral reefs, leaving only two narrow channels for people to pass through and almost completely closing the circle, fencing off the world from the outside with absolutely impregnable sheer walls.
They say that the Great Blue Hole is a huge reservoir that was carved out long ago by representatives of an ancient civilization for one purpose only known to them. And all because the circle of the pit is too even to be created only by nature itself.
An absolutely round well made of limestone in the very center of coral reefs, filled with deep blue water and decorated with bizarre stalactites, stalagmites, as well as amazing sculptures created by nature, was discovered forty years ago by Jacques Cousteau near Belize (one hundred kilometers from the continent).
The Great Blue Hole can well be called the entrance to underwater caves and the passages connecting them. It is located in the very center of Lighthouse Reef, a coral island (Atola), which is part of the famous Belize Barrier Reef, the total area of which is about 800 meters. It is not without reason considered to be the largest in the Atlantic Ocean, and in size it is second only to the Great Barrier Reef.
The diameter of this geological miracle is about three hundred meters, the depth exceeds one hundred and twenty - this is exactly the distance, and also surprisingly clear water combined with the stark white carbonate sand at the bottom, it gives the water an amazing hue, which is why it is nicknamed the Great Blue Hole.
At this point the water becomes dark blue because Blue colour itself has a very long wavelength of light, so when the sun's rays hit the water, all other colors disappear almost immediately, while the blue reaches the bottom of the pit and is reflected from it.
Due to its considerable size, this geological phenomenon was included in the list of “The Largest Holes on the Planet”, and is the fifth largest.
While such places appeared mainly due to direct human activity (mainly mining quarries), then, according to scientists, the Great Blue Hole was formed naturally, and is the largest (but not the deepest) of such places, thanks to which at one time UNESCO included it in the list world heritage.
Underwater well walls
The walls of the well, which are closer to the surface of the water (no deeper than 30 meters) are absolutely smooth and “decorated” with brown and green flowers. Then absolute darkness begins, and the inclined walls, gradually expanding, go down.
The first cone-shaped or helical stalactites and stalagmites, as well as various depressions and underwater tunnels on the walls of the underwater mountain can be found already at a depth of 50 meters, and on the western side of the pit there are numerous entrances to caves connected to each other by narrow tunnels.
The largest stalactites, sometimes reaching three meters in height, are located in the northwest. The first bottom begins here, it is slightly inclined and covered with sand and corals. This is where drivers (even experienced ones) finish their dive (depth - 41 m).
Bottom
Getting to the very bottom of the first cave (located at a depth of 70 m) and then getting out safely can only be done with the help of equipment specially designed for this, as Jacques Yves Cousteau did in 1972, and 20 years later by researchers from the Cambria Foundation.
At the farthest point of the cave, after swimming through a narrow tunnel, you can find yourself in the second “room”, which goes up, and from there you can get into the third. Due to lack of oxygen, very few people live here. sea creatures, and the walls are completely bare - practically nothing grows on them.
You can often see the skeletons of turtles and other marine life that accidentally swam here and were unable to get out.
Here, at one time, three human skeletons were discovered. According to one of the versions - lost drivers, since here you can easily lose your way: the bottom of the bowl is covered with silt, which, with the least movement, forms huge foggy underwater clouds that settle for quite a long time, and the supply of oxygen in the scuba gear runs out much sooner.
How did she appear?
The Great Blue Hole did not form immediately, but over a fairly long period of time. During the last ice age limestone caves formed here (at that time the sea level was much lower than now). They were discovered at a depth of seventy meters in the western part of the pit (naturally, filled with water), and were connected to each other by narrow passages. There are suggestions that these caves could easily be connected to the continent with the help of tunnels.
According to some data, about 200 million years ago an earthquake occurred, the consequence of which was a geological shift and the tilt of the main tectonic platform, which then consolidated in the state in which it is now.
This hypothesis is confirmed by the huge stalactites and stalagmites found at the bottom of the Big Hole, many of which are located at an angle of 10-13 degrees (stalactites can only develop perpendicularly downward and in no other way). Stone “icicles” were also discovered that appeared after the shifts earth's crust. Many stalactites were perpendicular to each other, thereby forming a lattice.
After the glaciers melt, the water level Atlantic Ocean rose, the caves were flooded, the vault collapsed, forming a karst funnel, a closed funnel-shaped depression that expands upward.
The limestone karst formations discovered by Cousteau during an underwater expedition - shelves and ledges located at different heights - 21, 49 and 91 meters from the bottom of the cave - confirmed that the appearance of this phenomenon occurred in several stages, since it was formed by the waters of the sea gradually advancing and flooding the cave .
The first absolutely flat protrusion of significant size was discovered fifty meters from the bottom, and it reduced the diameter of the pit by five to six meters, narrowing the vaults of the cave.
Undersea world
The Great Blue Hole is extremely popular among scuba diving enthusiasts. The minimum cost of one excursion per person is about $300 per day.
It is here that in your immediate vicinity you can see more than sixty species of corals, dolphins, huge grouper, sea turtles, snappers, spiny lobsters, octopuses, pink snails, harmless nurse sharks, as well as whale, reef and lemon sharks.
Divers rarely descend to a depth below thirty meters from the surface of the water, since it is not only very dangerous, but also swimming there is not very interesting, since the water in the cave practically does not circulate, so there is practically no oxygen necessary for marine life. Therefore, few people live at great depths of the Great Blue Hole, and the waters of this geological phenomenon are full of life only at the surface - fish lead an extremely active lifestyle here.
Secrets
On the one hand, Jacques Cousteau, having descended to the bottom of this amazing geological phenomenon, refuted the version that the Blue Hole of Belize is the work of representatives of ancient civilizations. But on the other hand, he was already mistaken once when, having examined the bottom of Lake Titicaca, he refuted the version that a city was located at its bottom. Thirty years later, another scientific expedition, armed with the latest technological developments, still discovered the remains of an ancient settlement there.
It is far from a fact that representatives of ancient races did not have a hand in creating the Great Blue Hole, who not only built a reservoir of an absolutely smooth and round shape, but also connected the coral island with the mainland of Latin America.
Belize is a country where the main attractions are the barrier reefs, the length of which is almost the longest among similar reefs on the planet. This is real fairy world for all those who care about diving. The Belize Reef contains an atoll, in its center there is a large sinkhole, the depth of which reaches 120 m. It is world famous as Great Blue Hole. Several hundred centuries ago, when the Ice Age reigned on Earth, this area was a huge cave, which after several hundred years sank under water. This fact was proven by Jacques-Yves Cousteau, who descended in a special underwater capsule to the bottom of the depression in the early seventies of the twentieth century and discovered geological traces of terrestrial life. From the air, the Blue Hole looks like a giant dark spot on top of turquoise waters Caribbean Sea.
Diving into the depths of the Blue Hole Possible for extreme sports enthusiasts of any level. But, of course, beginners should carry out such excursions only with an experienced instructor and no deeper than ten meters. But it is precisely at such a relatively shallow depth that you can meet the most beautiful representatives of the underwater world - sea turtles, giant grouper, hammerhead fish. These Caribbean waters are also home to reef sharks.
When diving into the Blue Hole, it is possible to see the ancient huge stalagmites and stalactites decorating the many small underwater caves of the depression. There was a legend that this depression was created by human hands about a million years ago - it has a very even cylindrical shape. However, this myth was refuted by scientists, including the legendary Cousteau. After careful study, the depression was recognized as one of the largest in both diameter and depth in the world and was included in the UNESCO heritage lists. Inside the Blue Hole there are many caves connected to each other. They are the object of study of many speleological expeditions, but have not yet been fully studied. Giant stalactites and stalagmites create additional danger for underwater travelers. In addition, careless movements inside these caves can lead to agitation of the waters, which threatens to raise silt deposits from the bottom, the water will become very cloudy and you may not be able to find your way back.
However, despite all the above points, these places continue to be very popular and relatively safe if you follow the instructions of specialists. And then the pleasure from seeing ancient natural monuments will not be overshadowed by anything.
Blue holes are underwater vertical caves that go deep and resemble large holes from above. This is a fairly common occurrence, but one such place stands out due to its enormous size. The Great Blue Hole is located in the center of an atoll called Lighthouse Reef and is the most popular diving site off the coast of Belize. Visible from a bird's eye view, the hole is 300 meters in diameter and goes 120 meters deep
This place became famous thanks to the explorer Jacques Cousteau and his team. It was they who first explored this underwater cave, the roof of which collapsed about 10 thousand years ago. The Blue Hole is part of the Belize Barrier Reef System, which covers more than 200,000 acres. 
The cave was formed when the sea level was much lower and when the ocean began to rise, the cave flooded and the roof collapsed. Belize's Blue Hole is considered the largest of its kind and has therefore been designated a World Heritage Site by UNESCO. 
Jacques-Yves Cousteau added Blue Hole to his list of 10 best places for diving. On his ship Calypso, he conducted a thorough study of the hole, measured its depth, and substantiated the method of its formation. Participants in the study descended on submersibles to the bottom of the hole and captured huge stalactites there, many of which were located at an angle. Hence the conclusion that geological shifts have occurred here repeatedly 
We included the Blue Hole of Belize in our “” list, where it is located in 5th place in size. It is relatively easy to reach from Belize City, the distance is only 96 kilometers, and can be quickly covered by speedboat or motor boat. Since the Great Blue Hole is a popular diving spot among tourists, dozens of different tours are organized here, including diving ones. This most famous landmark in Belize can surprise even the most experienced divers 
To dive here you need special skills. Divers dive here to depths of up to 135 feet and explore undersea world. These waters are home to many amazing species of fish, including giant grouper, nurse sharks and several types of reef sharks, including the Caribbean reef shark. 
Another famous blue hole is located off the coast of Egypt, in Dahab. This hole is famous in a sad way, and is known as the “Diver's Graveyard”. 
It is a lagoon surrounded by coral reefs about 100 meters deep. From a depth of 52-55 meters, the cave is connected to the sea by a strait. The rocks hanging over the strait are called Arch. The bad reputation of this place was created by unprofessional divers who dived in this place without sufficient qualifications and without the necessary equipment. The deceptive simplicity of completing the Arc often leads to a sad ending. In memory of the divers who died in the Blue Hole, a memorial was erected on the shore. But because large quantity For such divers, they stopped installing “placards” with the names of the dead, this scares tourists.
Great Blue Hole- a large blue hole located in the center Lighthouse ReefA, an atoll comprising Belize Barrier Reef. The hole is a round karst sinkhole with a diameter of 305 m, going to a depth of 120 m.
This geological formation 10,000 years ago was a system of limestone caves formed during the last ice age.
After the abundant melting of ice, the level of the Caribbean rose significantly lower, the roof of the cave collapsed, resulting in the formation of a particularly large karst sinkhole - a common form of relief along the coast of Belize.
The researcher of this natural wonder is Jacques-Yves Cousteau. Arriving here in the early 70s of the last century, he nicknamed her “The Great”. This is where the name comes from, the Great, or Great Blue Hole.
In 1972, Cousteau, after research, confirmed the theory according to which the Great Blue Hole was formed. The expedition members descended to the bottom of the cave in single-seat submarines. As a result, massive stalactites were discovered.
The perimeter of the cave is surrounded by the Lighthouse Reef Atoll, which is part of the Belize Barrier Reef. From the outside, you get an amazing natural picture - a ring-shaped island, surrounded by turquoise water, with its shores holding deep blue water inside.
Cousteau called it one of the best places for diving. That's how it is. Despite the distance from Belize, 96 kilometers, the place is popular among divers. There is an abundance of fish here, including nurse sharks, Caribbean reef sharks and groupers.
Today, the Great Blue Hole is of value to travelers, athletes, ecologists, speleologists and many people who care about nature. The cave is included in the UNESCO list of natural world heritage sites.
Great Blue Hole– a popular place, one of the ten best diving spots in the world. At a depth of about 70 m in the west of the bowl there are entrances to caves filled with water. These caves are connected to each other by narrow passages. In one of the caves, the skeletons of 3 people were found - these were most likely lost divers who could not find a way out of the caves.
But, as a rule, divers dive no more than 30 m - this is due to the fact that there is not enough oxygen at depth and therefore life flourishes only closer to the surface.
Great Blue Hole in Belize – (English Great Blue Hole) is a sinkhole atoll located in the center of Lighthouse Reef and part of the Belize Barrier Reef.
Synonyms - Great Blue Hole, Great Blue Hole, Great Blue Hole
The Great Blue Hole is located in Caribbean Sea 96 km from a small state Belize, what in Central America. The uniqueness of the blue depression is that up to today At great depths, ancient systems of caves and gorges have been preserved.
Coordinates: 17.315278, -87.534444
IN 1972 year, the famous French navigator Jacques-Yves-Cousteau on his ship " Calypso“studied the depression, determined its dimensions and came to the conclusion that this formation is a creation of nature itself, and not the work of man.
Jacques-Yves Cousteau called the depression " Great", and also added it to the list 10 best diving spots, and in the 70s even released a film dedicated to the discovery of the Great Blue Hole.
The Blue Hole is a rounded sinkhole 300 meters in diameter and depth 120 meters.
In ancient times, this place was the site of an extensive chain of limestone caves of various sizes, which were destroyed and flooded during the Ice Age.
As a result of a strong depth difference, the water in the blue hole is much darker. Thanks to this, a stunning bird's eye view opens up - turquoise sea water washes the Lighthouse Reef Atoll, inside of which you can see a dark blue hole.
Rare tides on the surface of the Big Hole form strong whirlpools, which are capable of pulling to the bottom not only sea inhabitants, but also ships, boats, etc. History has recorded cases where people died in the blue hole.
With the onset of low tides, significantly the rate of water vibration increases, which contributes powerful eruption water masses. Sometimes such fountains throw out various debris from the bottom of the caves, and the water becomes cloudy and dirty due to silt accumulations.
In the lower layers of the pit, water practically does not circulate, so only algae “lives” at the bottom of the depression.
But in the upper layers of the hole there are really a lot of marine inhabitants. At a depth of 10 meters live various rare fish species: huge groupers, stingrays, nurse sharks, lemon sharks, lion fish and others.
Also, the waters of the Great Blue Hole are filled with unusual plants, giant turtles, spiny lobsters, colorful crabs and coral reefs.
An underwater walk at a depth of 70 meters in the western part opens up for divers a whole system of caves and recesses, which are connected to each other by narrow passages. This area is very dangerous and you can easily get lost here.
Big hole far away not the only one of its kind, but it is she who is considered the largest among similar karst formations. This is why the Belize Barrier Reef listed as a UNESCO heritage site.
Great Blue Hole - VIDEO
Diving into the “depths” of the Great Blue Hole gives you the opportunity to see more than just beauty seabed, but also to plunge into the secret world of cave rooms, the age of which more than a million years.
Great Blue Hole is a relatively safe place for tourists and divers. Every year the number of visits to this place is sure to increase.