Scuba Diving

These amazing underwater places will make you want to go diving right now

© Tom St George -
Written by Will Gray
If you’re tired of reefs and tropical fish and want a more adrenaline-fuelled underwater adventure, take a look at these nine extreme dive sites where you can step things up to another level.
Exploring underwater mazes in Mexico, Florida or Australia, swimming over unexploded mines in Thailand and meeting creatures of the night in the dark waters of Hawaii are the most extreme diving experiences you can get.
But be warned, these adventures don’t come easy.
Taking on some of the world’s most dramatic dives not only requires expert training, high tech equipment and, in many cases, a good helping of Trimix gas, it also involves a huge amount of guts. And perhaps a touch of insanity.
WIll Gadd scuba diving in Ilulissat, Greenland on August 28, 2018.
Diving is always a leap of faith with the risks involved
But if you’ve got all that, and you fancy a bit more adventure than another trip to see Parrot fish and waving coral, check out these nine extreme dive destinations.

1. Temple of Doom

  • Where: Cenote Calavera, Tulum, Mexico
  • Type: Cenote Sinkhole
This underground labyrinth is one of the most challenging of Mexico’s famous Cenote sinkhole sites, taking divers through a disorientating maze of limestone tunnels, ledges and caverns.
A rickety pipe ladder leads through a 7m hole into a multi-level cave system filled with a mix of salt and fresh water. It’s lit by beams of sunlight through three openings, but get out of the sunlight and it’s easy to get lost.

2. Diepolder II

  • Where: Brooksville, Florida
  • Type: Cave system
This may look like a normal pond from surface level but beneath the water it drops down 110m into the Diepolder II and III cave system, continental America’s deepest cave.
A scuba diver navigates under water during a dive Diepolder II near Brooksville, Florida.
Access to the Diepolder caves is heavily vetted
Discovered in 1978, it’s entered through 60m-long vertical tunnel that goes directly down into a 30m-high cavern, with incredible pinnacles of rock rising up six metres from the cavern floor.

3. Blue Hole

  • Where: Dahab, Egypt
  • Type: Ocean tunnel
This underwater tunnel, featured in Luc Besson’s 1988 film The Big Blue, goes down 120m and has a reputation as one of the world’s most dangerous dive sites because of the risk of nitrogen narcosis disorientation.
Handled with care, however, it rewards expert divers who reach its famous underwater arch, 56m below the surface, with an adventure through a 26m-long tunnel out to a giant opening into the Red Sea.
An  aerial image of the Blue Hole dive site in Dahab, Egypt.
The Blue Hole dive site as seen from above

4. The Shaft

  • Where: Mount Gambier, Australia
  • Type: Cave system
This giant cave system is entered through a tiny manhole in the middle of a field. It leads down a narrow 8m-long shaft to a water-filled cave from which two tunnels, one at either end, descend to depths of 85-120m.
Gear must be lowered down to divers through the shaft because it is too tight to fit through wearing it, and the site is carefully controlled by the Cave Divers Association of Australia, with dives now restricted to 40m.
The entrance to the The Shaft diving location in Mount Gambier, Australia.
The Shaft is full of very dark and winding caves so caution is advised

5. Samaesan Hole

  • Where: Samae San Islands, Thailand
  • Type: Open ocean
Not for the feint hearted, this spot in the Gulf of Thailand drops 85m down to a former military dumping ground, where the seabed is littered with unexploded bombs.
It requires experience and high tech equipment to reach its greatest depths, where sunlight rarely penetrates. Unless done at slack tide, divers can drift miles from their start point into a busy area for tanker traffic.

6. Eagle’s Nest

  • Where: Weeki Wachee, Florida
  • Type: Cave system
This is known as one of the ‘Mount Everests of cave diving’ with cavernous chambers and crystal clear waters – yet from the surface it looks like nothing more than a scum-covered pond.
The cave system reaches depths of up to 90m and begins with a narrow chimney-like descent into the ‘Main Ballroom’, which then leads on to long tunnels and narrow passageways snaking further underground.

7. Pelagic Magic

  • Where: Kona, Big Island, Hawaii
  • Type: Open ocean
This night dive is perhaps more freaky than extreme, with divers connected to the underside of a boat and suspended in pitch-black water over a deep channel that descends hundreds of metres.
The reason for doing it, however, is spectacular. In the darkness, deep ocean bioluminescent creatures rise to the surface, creating a truly unique psychedelic show of colour with strange beings coming at you from all sides.
A deep ocean bioluminescent creature as seen at the Pelagic Magic dive location in Kona, Hawaii.
You'll just won't know what you'll find diving at Pelagic Magic

8. Chuuk Lagoon

  • Where: Caroline Islands, Micronesia
  • Type: Wreck
Buried beneath the water in this remote region of the central Pacific is the remains of a Japanese naval base and all the boats and planes that went with it – including the well-preserved San Francisco Maru.
Discovered in 1969 by Jacques Cousteau, the 117m-long cargo ship sits on the seabed 63m down with its deck around 50m from the surface and its hold contains mines, torpedoes, three tanks and several old trucks.
A Toyota KB (designated Type 1 in military service) truck in the hold of the Hoki Maru wreck, Truk Lagoon, Micronesia.
There's a treasure trove of wreck items to see in Chuuk Lagoon

9. Petermann Island

  • Where: Lemarie Channel, Antarctica
  • Type: Open ocean
One of the most remote dive spots on the planet, this island has 10 locations where you can swim amongst incredible underwater ice sculptures and encounter gentoo penguins, leopard seals and even whales.
It’s only accessible on organised trips and it takes a brave person to get in the water. Divers must wear heated suits and masks and have cold water certifications – and even then, 30 minutes turns them into ice blocks.