Two divers jumped into a dark pit and discovered something truly astonishing.

Australia’s vast Great Barrier Reef is a hotspot for divers and those with a thirst for adventure. And two divers proved that it still contains some undiscovered wonders. The video of their plunge into an underwater world takes us on a journey of discovery that would probably surprise even the most experienced of explorers.

The footage was taken in October 2017, which falls within the peak season for excursions around the Great Barrier Reef. During this period, the crowds of visitors are pretty much guaranteed comfortable weather and, most importantly, clear water – vital for glimpsing all the exotic wildlife that lives there.

Image: Facebook/Back to Basics-Adventures

The video was filmed by Back to Basics, an online community that shares photos and videos of outdoor adventures. Their Facebook tagline goes like this, “Spearing, fishing and making the most of this unreal environment around us!” With over 28,000 likes on their page, the group’s videos inspire viewers with incredible landscapes and epic nature discoveries.

Image: via Ocean Alliance — Image: Ocean Alliance

The specific location of where the video was shot has not been revealed, although we do know that it was filmed on an island somewhere in the vast Great Barrier Reef. And happily, the footage captures the incredible experiences that the divers had there.

The film opens with a shot of a mysterious-looking hole, which appears to be located in a secluded, rocky beach. The hole itself is full to the brim with water, but because of the camera angle, it’s unclear what lies beneath the surface. And the divers are not alone, either; with them are two fishermen and another man who is capturing events on his phone.

The video then shows one of the divers taking a run up to the hole. Clad in a black wetsuit and snorkeling goggles, he dives headfirst into the hole. For a few seconds, the man disappears completely as the others look on.

Seemingly surprised by what he’s seeing, the man filming proceedings on his phone approaches the diving spot to get a closer shot. The second diver – who is filming the video – also edges nearer to the hole while his buddy is underwater, presumably hoping for a good angle when his friend subsequently re-emerges.

A few seconds later, though, the first diver bobs up out of another hole in the rocky beach, a few feet away from one that he dived into. And looking at the rock that covers the water in between the two holes, many viewers are probably left wondering what lies underneath it. Fortunately for them, though, they’re about to find out.

The cameraman then turns the camera on himself. He’s also wearing snorkeling goggles, and he subsequently takes a deep breath and jumps into the air. Now, as the diver hits the water feet first, viewers are taken with him to discover what lies beneath the surface.

For a few seconds, bubbles are the only thing that we see as both the diver and camera plunge underwater. The bubbles then disperse, though, to reveal that the diver has made an incredible discovery. It turns out, in fact, that he has dived straight into the heart of a coral reef.

As his surroundings become visible, the diver keeps swimming forward, the camera turned on himself the whole time. He is closely surrounded by coral on either side of him, while at points the reef is above him, too, forming a sort of cave.

As the diver swims forward, dappled sunlight streams through the water, providing viewers with brilliant snapshots of the coral. The light hits the reef, and the camera captures the coral’s beautiful colors and the turquoise shades of the water.

Swimming on a little further, the cameraman spots the legs of another diver, signaling that he has reached the second hole. After being underwater for a total of 19 seconds, he bursts out of the water with a triumphant “Woah! How about that!”

Image: via Crayfish Farms — Image: Crayfish Farms

Someone off camera congratulates the diver, saying “Well done Geoff!” as the other diver looks over his shoulder and laughs. And in the meantime, two more fishermen have come over to check out the incredible diving spot.

Image: Facebook/Back to Basics-Adventures

And it wasn’t just the onlookers at the scene who were interested in the underwater cavern. Indeed, the video, which was shared by Back to Basics across their social media channels, has garnered millions of views. The captions on Facebook and YouTube reveal that the divers jumped into the hole because they thought that they’d seen a crayfish, a type of water crustacean that looks very similar to a lobster.

And the comments on Facebook showed that many viewers were impressed by the footage. One user wrote, “Got to love the reef holes on northwest,” while another pointed out that it was “literal free diving.” Some took a more light-hearted approach, though, commenting, “Danger to scratch your back.”

On Instagram, meanwhile, users wasted no time in commending the bravery of the divers. One user wrote, “I would [be] so scared of getting lost under there,” while another commented, “I’d be worried I’d get stuck under there and drown.” And the first diver received a special shout-out, with one user claiming, “The first boy is the best diver ever.”

Image: via Alana Olendorf E-Port — Image: Alana Olendorf E-Port

It also seems that the video has inspired others to make a trip to the Great Barrier Reef, with one user on Instagram commenting, “Wow, one new bucketlist place on my list. Thank you for sharing this.” The reef has always been at the heart of Australian tourism. The mass of colorful corals attracts a staggering two million people annually, in fact, which brings in around $4 billion each year.

However, extensive scientific research indicates that the reef is in grave danger. As our planet heats up, coral is dying at a frightening pace. The Australian Institute of Marine Science has reported that from 1985 to 2012 the reef has lost approximately half of its coral covering.

For now, though, the reef continues to attract millions of visitors. With experiences such as diving, boat tours and snorkeling on offer, there is still much to explore in the reef, including some little known corners. Indeed, it turns out that a crayfish can lead you to all kinds of exciting places.