Dudarev Mikhail / Shutterstock
Ask any scuba diving expert or enthusiast and they will tell you that, hands down, the Blue Hole in the Gulf of Aqaba is one of the most, if not the most, dangerous dive site on the planet. That is probably exactly why so many people are attracted to it. This submarine sinkhole goes down 426 feet. More than 100 divers have drowned there which is why the Blue Hole’s nickname is the Diver’s Cemetery. The main reason is that they end up diving too deep because they get confused due to nitrogen narcosis, caused by the anesthetic effect of certain gases at high pressure, and can’t find the tunnel connecting the hole to open water. One victim brought a camera with him. The video shows how he lost consciousness after a few minutes and never surfaced.
This swimming hole near Austin, Texas may not look like much from the surface but looks are deceiving. There are four different entryways to explore. Narrow spaces can be a huge problem, especially after the third one. The gravel is loose and you can very easily kick it causing visibility problems. Divers can’t see, get confused, panic and breathe too fast using up the oxygen they have in the tank. One way even looks like it leads to open water but it actually traps you there. At least eight people have died in Jacob’s Well.
Tatiana Belova / Shutterstock
It’s hard to think of a colder and more isolated place to dive. Temperatures are often below -40 degrees Fahrenheit and winds are very strong creating some deadly conditions. Most of the diving happens in December and January when it’s summer there and the water is about 30F. The ice and weather change quickly and unpredictably. The water above you may freeze before you decide to come out of it. The cold water means higher air consumption rate and more energy burned. Divers can get tired very quickly.
The Black Hole is another very famous diving site. It’s open only for scientific expeditions. As you go down, you pass through about three feet of toxic bacteria containing high concentrations of hot hydrogen sulfide. It’s between oxygenated water above it and the oxygen-free water under the gas. The latter is similar to the ocean water on the planet billions of years ago.
If you’re looking for dangerous caves to dive in, Mount Gambier will not disappoint. It has a lot of them. The most hazardous location, however, is the Shaft Sinkhole. The entrance is too narrow and divers have to take off their equipment to climb down a ladder to the water. The visibility is bad – passages are very dark – and the depth is making the dives very difficult. Divers can easily miscalculate how much air they need.
Rich Carey / Shuterstock
The problem with this dive is the poisonous sea snakes you’re almost guaranteed to encounter. You can see as many as 60. Braveness is a must-have quality; simply “adventurous” won’t do. Sea kraits are all over the Snake Ridge. The sea may look like a bowl with spaghetti (the snakes) when viewed from above. The venomous reptiles can grow up to five feet, sometimes even 10. They are not known to be very hostile but you still don’t want to provoke them. They will swim directly at you, at which point you have to somehow find a way to stay very calm. Any quick reactions will lead to them chasing you.
They call it the “Mount Everest” of cave diving. The Eagle’s nest has good visibility and wide entryways. Still, this sinkhole is only for advanced divers. About 300 feet deep – some spots even go as deep as 1,035 feet – it has to be approached with extreme caution. Common mistakes people make is not descending and ascending really, really slowly. Nitrogen narcosis is a realistic possibility. Divers begin to feel euphoric and confused. They breathe too fast, using up the oxygen, and get lost.
One of the most popular dives in Mexico is the Cenote Esqueleto, a.k.a. the Tempe of Doom. It has a lot of caverns and very narrow passageways that resemble a maze. The only way to get in is by jumping. There is no ladder or stairs. It’s easy to get lost there because it gets very dark. That can easily lead to confusion and lack of coordination.
The Samaesan Hole is almost 300 feet deep. It used to be a dump where the military threw out bullets, shells, ammos. It also has a lot of unexploded bombs. Another danger is the very strong currents and the almost impenetrable darkness.
Wata51 / Shutterstock
The Blue Hole in Belize is one of the most stunning scuba diving locations when seen from above. It’s beautiful underwater as well – clear waters, rich sea life, lots of sunshine. The Blue Hole is more than 400 feet down into the earth. Some divers even try to go deeper. But it gets very tough after 120 feet. Things get tricky after that as strange-looking formations appear that look like icicles hanging from the roof and darkness settles in. Divers are not recommended going below 90 feet. When they do, nitrogen narcosis is a high risk. Their judgment is impaired and they can’t think straight or fast. Some can even lose consciousness. About 150 divers have died in the Blue Hole over the past 15 years.
The Ginnie Springs seem like the perfect place to dive into. The water is warm and clear. Devil’s Eye, Little Devil and Devil’s Ear are not so friendly though. Very strong current moves underwater endangering the divers. The narrow vortex opening is almost certain to move the scuba equipment around. There are more than 30,000 feet of passageways, some of which are very thin, forming a labyrinth to explore.