Venturing down into the depths of the ocean isn't for everyone.
With so much of it still an undiscovered mystery, the experience can often be a disturbing experience, as well as a serene one.
That was perfectly demonstrated by an expedition a few years ago that aimed to get to the very bottom of the so-called Great Blue Hole in Belize.
As scary as it may be, the mission proved that sometimes disturbing discoveries can be worth it.
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This flooded sinkhole is one of the largest on Earth, coming in at around 300 meters (984ft) across, and 125 meters (410ft) deep.
That might sound like barely a ditch in comparison to the scale of the ocean, but it's deep enough that recreational scuba divers can't reach the bottom, or certainly shouldn't try.
It wasn't until 2018 that a submarine from Aquatica Submarines managed to get to the very bottom, to see what was down there.
And the anticipation was strong.
However, as the crew got down past the 90-meter mark the amount of marine life started to dwindle down to pretty much nothing - What they actually discovered instead, was much more disturbing.
By the time they got to the sea floor, there was almost no marine life at all. Zilch.
They discovered this was thanks to a toxic underwater layer of hydrogen sulphide across the sinkhole which stopped oxygen from getting to its lowest levels.
Erika Bergman, who was on the expedition, explained that it was a little like a graveyard down there, telling Business Insider: "We found conchs and conch shells and hermit crabs that had fallen into the hole and suffocated."
It's almost like the sinkhole is a sort of trap for underwater life, and if any creatures are unlucky enough to fall in without being able to swim away, there's no escape from an unfortunate fate.
Sadly, though, it wasn't just marine life that was discovered post-mortem, but also the bodies of two divers who had died on a previous expedition at some point.
Bergman said: "We found the resting place of a couple of folks, and we very respectfully let the Belize government know where we found them. Everyone decided that we would just not attempt any recovery. It’s very dark and peaceful down there, just kind of let them stay."
That wasn't the only human activity discovered, though, because Bergman also talked about how the team found bits of litter down at the bottom of the sinkhole, including empty soda bottles.
Whilst the bottom of a toxic sinkhole can't support any life, you still find human garbage, which is a pretty depressing thought actually.