People were shocked at the sight of such a big mammal so deep underwater.
Divers were treated to quite the spectacle thousands of feet deep underwater - one of the places you really don't expect to be bumping into surprising guests.
The deep ocean is vast and unexplored, so it's no surprise that we know more about space than we do the depths of our planet.
And while the ocean is unbelievably deep, it hasn't stopped people from trying to explore these dark depths.
To date, the deepest point ever reached by man is 35,858 feet below the surface of the ocean. But, as I'm sure you can imagine, this is no easy feat.
In fact, it's rather impressive.
Scientists suspect there are scores of different kinds of marine life in the deepest parts of the ocean that no person has ever seen before.
And if I'm honest, I am fine with that. They can have all that deep, dark, terrifying water, and I'll stay on land, where it's nice and safe...ish.
In some footage that dates back to March 2006, divers were going down to inspect a gas line owned by Helix Energy Solutions, which sits 3,000 feet down from the surface.
Everything seemed normal until a large presence loomed into focus.
Apparently, the marine animal that verged towards the divers was a whale of some kind (thought to be a sperm whale), and many might not have been aware that the ginormous mammals could dive so deep.
This isn't the deepest a whale has been known to go, however. According to the Natural History Museum, the deepest whale dive recorded so far was made by a Cuvier's beaked whale.
A 2014 study found that one of the eight whales that was being tracked via satellite tagging went as far as as 2,992 meters. Impressive!
Typically, Curvier whales will only go as far as 2,000 meters. Meanwhile, sperm whales have been known to regularly dive 1,000 to 2,000 meters deep - around the same depth as the gas line in question.
The clip of the Helix Energy Solutions gas line has wowed a lot of people online.
One person wrote: "Amazing how a biological creature with bone and organs can withstand the intense pressure that deep. We need to build machines with very thick metal to get that deep, and even then they are sometimes crushed like tin cans.
"Also the fact that whales can't breathe under water yet he is just cruising along the bottom 3000ft deep."
"It's crazy to think we haven't explored the deeeeeeeeeeeeep ocean. What's down there?" asked another.
A third person wrote: "Make us realize that we still have no idea from what is down there, like from the few creatures we have seen before on certain deep sea videos, I'm sure there is way more down there."
I wonder what else lurks below the water's surface...