Would you believe us if we told you that more than 80 percent of the world’s oceans are unexplored? Yes, according to the National Ocean Service, much of the vast expanse of water covering our planet hasn’t even been fully mapped and investigated. But even of what we have seen, there are countless unexplained entities which baffle scientists to this day. So, let’s explore some of these mysteries and examine a few that have actually been solved, too.
40. The weird purple blob
A group of researchers on the research vessel E/V Nautilus were left baffled in 2016 after discovering a bizarre purple blob resting on the Californian seabed. So, the experts decided to catch the thing in order to figure out what they’d just found. After some analysis, the team concluded that the alien-looking creature might actually have been a pleurobranch. Though they weren’t certain. According to National Geographic, the pleurobranch is related to the snail, but its “ancestors shrugged off the shell millions of years ago.”
39. The milky sea
Back in 1864 Captain Raphael Semmes and his crew were sailing aboard the CSS Alabama when they noticed something astounding. Amazingly, the seas around their vessel had started to glow. As Semmes himself wrote of the experience, “The whole face of nature seemed changed…” At the time, these people couldn’t possibly have understood what was causing this so-called milky sea. But today, the BBC notes that phenomena of this nature are caused by billions of trillions of bioluminescent bacteria.
38. The Baltic Sea Anomaly
If you are a fan of UFOs, then you’re going to love this one. A group of divers exploring the depths of the Baltic Sea came across a circular object which was around 1,000 feet in length. Yes, the aptly named Baltic Sea Anomoly resembles an alien space ship, and it has experts totally baffled. According to the website Marine Insight, it “still remains one of the unsolved intrigues and ocean mysteries of the world.”
37. The Kraken
Some of you may have heard of the Kraken. For those of you who haven’t, this terrible monster of the ocean has been described by centuries of artwork. It is a colossal, multi-limbed beast, which was said to have pulled ships down to the bottom of the sea. Sure, all of this sounds far-fetched, but is it possible that such a creature actually existed? Well, some scientists have speculated that the Kraken may well have been a giant squid. Some of these cephalopods are thought to grow up to 66 feet in length, after all.
36. The mysterious ‘bloop’ sound from the deep
Back in 1997 a deafening “bloop” sound was picked up in waters near South America. And this wasn’t just any normal sound. No, this noise was actually one of the loudest ever recorded in history, according to Live Science. So what was it? Well, the National Oceanic and Atmospheric Administration believes that it was likely the sound of a massive iceberg splitting apart.
35. The immortal jellyfish
The life cycle of a jellyfish is fascinating. The creature starts out as a larva – before finding something to attach itself to. It then transforms into a polyp, which replicates and creates a whole colony of them. Under the right conditions, these will then bloom and young jellyfish will emerge. But if this wasn’t amazing enough, when a species known as Turritopsis dohrnii dies, its cells regenerate as polyps again. In other words, this immortal jellyfish has started its life cycle once more.
34. The Yonaguni Monument
In 1985 a bizarre discovery was made deep in the seawaters of a Japanese island known as Yonaguni. Strange as it seemed, an enormous staircase appeared to be resting underwater. All these years later, it’s not clear if this was created by ancient human beings or if they emerged naturally.
33. Square waves
It’s a strange sight to behold, but sometimes waves in the sea can arrange themselves into square formations. Such a phenomenon occurs when separate waves approach one another from varying directions. And though they look amazing, you should be mindful that square waves are dangerous if you get caught up in them.
32. Puzzling holes along the Californian seabed
Researchers investigating the waters off Big Sur in California were surprised to note a series of indents on the seabed. They found about 15,000 of these hollows, and the team couldn’t quite figure out what was causing them to emerge. Many of the holes had garbage inside, so maybe dumping had something to do with them? Naturally, more studies will be needed to figure this one out.
31. Antarctica’s Blood Falls
A nightmarish waterfall is gushing somewhere in the McMurdo Dry Valleys of eastern Antarctica. Here, blood flows over the white ice – or so it would seem. You’ll be glad to learn that this liquid isn’t really blood, though. According to the BBC, the water comes from a particularly salty sub-glacial body of water. It’s still a creepy sight, though.
30. The Hidden Beach of Mexico
A secret paradise awaits on one of Mexico’s Marieta Islands. Here, a massive hole in the ground transports people into a beautiful beach wonderland. But how did this unique spot come to be? Well, one theory is that the Mexican military tested bombs on the island in the early 1900s and it inadvertently created the place.
29. The missing submarines of 1968
It was a bad year for military submarine crews around the world in 1968. Four vessels were lost that year without anyone ever figuring out what had happened to them. These were the Israeli INS Dakar, Soviet K-129, USS Scorpion and the French submarine Minerve. The latter vessel was finally discovered at the bottom of the Mediterranean in 2016. But even so, we still don’t know why it sunk in the first place.
28. Frost flowers
Every winter, the Arctic Ocean produces a spectacular phenomenon thanks to the specific conditions present in the region. To put it simply, the surface of the water becomes covered in beautiful and strange structures. These so-called frost flowers are icy formations in which microorganisms thrive. And yes, they’re quite the thing to behold.
27. The sea serpent
Over the years, various naval crews have claimed to have seen a fearsome beast in the waters around them. Described as a “sea serpent,” this aquatic monster apparently measured around 100 feet in length. But what exactly was this bizarre beast? Well, we can’t be sure, but it’s believed that it may have been an oarfish.
26. The missing island of Bermeja
As far back as the 16th century, the island of Bermeja was shown on maps to be near the coast of Mexico’s Yucatan Peninsula. But after some time, this place stopped being plotted into geographic charts altogether. So, what happened to the island and where did it go? It was last accounted for on a map in 1921, but nowadays there’s no sign of it.
25. St. Elmo’s fire
Have you ever seen what can happen when a boat sails into a substantial electrical field? Well, reactions with sharp objects such as the mast can cause electrons to light up in vivid colors as if they were the result of magic. This occurance is known as St. Elmo’s fire, and it takes it name from one of the patron saints of sailors: St. Erasmus of Formia.
24. Red tide
If you happen to be out on the ocean during an event known as “Algal Blooming” you might be shocked by what you see. The water will have turned red – taking on the appearance of a sea of blood. This is actually the result of algae. Sure, it’s not real blood, but the water can nonetheless be hazardous for the creatures it engulfs.
23. The unexplained Jian Seng ghost ship
Back in 2006 a vessel was found drifting along Australia’s coast without a crew aboard. We know that the boat was called the Jian Seng, yet not much else could be figured out. Investigators couldn’t tell this ghost ship’s tale, and it’s still a mystery today. Yep, we don’t have a clue who was once on this craft or even what happened to them…
22. The underwater waterfall of Mauritius
Try to get a bird’s-eye view of Le Morne island in Mauritius, and you’ll soon notice something crazy. Silt and sand on the floor’s ocean runs down in a manner which makes the whole island look like its being sucked into a huge drain. But be warned, this is actually just a trick of the eye involving the particular manner with which the sand moves.
21. Marching octopuses
In 2017 a group of dolphin-watchers noticed something weird in Wales. What appeared to be a “blob” was crawling around 30 feet in-land. And when these individuals investigated further, they found that this strange entity wasn’t on its own. In fact, it was just one of up to 30 octopuses that were marching away from the sea. But why would creatures which belong in the ocean be crawling on dry land? Well, to this day we have no idea.
20. Bimini Road
Greek legend has it that a city known as Atlantis was lost to the sea thousands of years ago. This tale has enthralled people for centuries, but in 1968 it looked like proof of this mysterious place had finally emerged. A number of slabs resembling a road were discovered along the seabed of North Bimini Island in the Bahamas. So, had we discovered evidence of the famed city? Sadly not, as subsequent investigations found that the rocks were actually natural formations.
19. Fog tsunamis
You’d be forgiven for panicking if you looked outside and were greeted by the sight of a fog tsunami. After all, it would seem like a giant wave is about to sweep over you and everything else in its path. But try to stay calm. This natural phenomenon is just condensation mixing with cold ocean water – creating a huge amount of fog.
18. Underwater crop circles
We’re all familiar with crop circles, and they’ve been subject to countless theories over the years. Yep, they’re an intriguing mystery. But the same goes for similar patterns that occur underwater. Some people have suggested that underwater crop circles are actually designed by extraterrestrials. Though a more reasonable explanation is that they’re made by pufferfish, according to Marine Insight.
17. Colorful icebergs of Antartica
When we think of the icebergs in Antarctica, we tend to picture them as white blocks with few other embellishments. But sometimes these formations can turn blue and stripey. When certain particles get trapped in the ice, some beautiful patterns can then emerge to blow observers away.
16. The changing behavior of humpback whales
Humpback whales were once known to spend a lot of time on their own – swimming the oceans without anyone for company. But in more recent times, entire groups of the creatures have been seen eating together near the South African coast. And scientists have no idea why this change to their habits has occurred.
15. The Mariana Trench
The Mariana Trench is found not far from the island of Guam, and it’s believed to be the deepest place on our planet. It’s a part of the ocean that continues downward for an incredible 7 miles. And if you don’t think that’s far, consider this. Mount Everest is roughly 5.5 miles high, so you can appreciate how huge this gorge really is. And we know very little about what’s going on down there. After all, only three people are known to have explored it.
14. The green flash phenomenon
A strange effect can sometimes be observed in coastal areas when the sun rises and falls each day. Interestingly, a flash of green light can be seen for just a few seconds. It looks like something quite magical, but there’s a perfectly reasonable scientific explanation. Basically, the sunlight is being broken up and is then seen as a green beam.
For those of you who don’t know, a maelstrom is formed when a pair of contending currents in the ocean converge. These whirlpools can pull things into their spiraling vortex and drag them down to the seabed. A maelstrom is an enthralling phenomenon – another example of the sheer power and complexity of nature. But make sure you don’t get swept up in one.
12. The Bermuda Triangle
As Christopher Columbus traveled the seas on his way to the New World, he apparently looked to the sky and saw a ball of fire dropping from the sky and into the ocean. Yes, though it wasn’t called it at the time, Columbus was in the Bermuda Triangle. In the years since, dozens of airplanes and ships have vanished in the area. And the reason for this continues to confound scientists.
11. Where did the oceans come from?
The ocean is full of strange and mysterious entities. But have you ever wondered where it actually came from? Scientists still aren’t quiet sure how our planet came to be engulfed in so much water – though theories do exist. One, for instance, posits that several enormous icy asteroids hit the Earth and led to the things we see today.
When the surface of a sea freezes, the salty water can be pushed deeper and down towards the seabed. Once this happens, this water can itself freeze and ultimately form a structure known as a brinicle. These strange formations can most often be seen in the waters of the North and South Poles.
9. Frozen methane bubbles of Canada
In cold places like Canada, a beautiful phenomenon can sometimes be observed in the ice. When organic matter ends up in a body of water, it might sink and be consumed by microorganisms that then give off methane gas. This travels towards the surface in the form of bubbles, which sometimes freeze and create these stunning shapes.
8. The mysterious Mary Celeste
In 1872 a ship known as the Mary Celeste was at the heart of a great mystery. The vessel set off from New York City and was destined for Italy. But it never arrived. Instead, Mary Celeste was discovered by British sailors drifting in the Atlantic without a crew. Nobody knew what happened to those on board – and we still don’t.
7. Florida’s mystifying blue hole
Blue holes are sinkholes found on the ocean floor, and very little is known about them. But in August 2020 a team from the U.S. Geological Survey, the Georgia Institute of Technology, Florida Atlantic University and the Mote Marine Laboratory set out to explore one off the coast of Florida. Scientist Emily Hall – who is from the latter organization – remarked to CNN in 2020, “A lot of people have been comparing it to going into space. We don’t know what we’re going to find out there, but we’re going to keep exploring it.”
6. The Stronsay Beast
Of course, we all know that the most famous mythical beast of Scotland is the Loch Ness Monster. But have you ever heard of the Stronsay Beast? In 1808 people were left shocked after animal remains washed up on the shores of Stronsay island. According to the Scotsman, locals noted that the alien-looking creature was “of incredible length, with a long slender neck, three pairs of legs, a tail and a hairy main.” But the mystery may have since been solved. A surgeon called Sir Everard Home went on to examine the creature’s neck bones and skull. He subsequently concluded that it was a basking shark.
5. Rogue waves
Gigantic waves undoubtedly make for dramatic scenes in Hollywood disaster movies. But it turns out that these actually occur quite often in real life, too. So-called “rogue waves” can materialize very suddenly, and they can be extremely destructive. Studies conducted from satellites have found that these waves are actually quite frequent.
4. Underwater ghost trains
Paul Hepler was in for quite the surprise when he attempted to map out the seabed near New Jersey in 1985. Amazingly, trains dating back almost a century were lying under the water. And the crazy thing is that it’s still not clear how or why they ended up there.
3. A foamy beach
Sea foam is a common occurrence when waves crash into a coast, but sometimes it can totally cover a beach. This can happen because of the activities of microorganisms, though human activities can also contribute. As environmental scientist Matthew Reidenbach told Atlas Obscura in 2019, “Humans – when they dump nutrients into the water – can make [sea foam] much worse.”
2. The Devil’s Sea
Sure, you’ve heard of the Bermuda Triangle. But what about the Devil’s Sea? Well, it turns out that vessels have disappeared from the latter in mysterious ways – just as they have done in the Bermuda Triangle. The Devil’s Sea is found just south of Tokyo, and around 20 U.S. submarines went missing there during WWII alone, according to Buzzfeed. Incredibly, the publication added that vessels twice as big as the Titanic have also disappeared in these waters.
1. The ocean floor
The ocean is an incredibly mysterious place, with so many strange puzzles yet to be solved. The National Oceanic and Atmospheric Administration notes that an astonishing 80 percent of it hasn’t yet been explored. Yet all of this will change. Studies such as the so-called SeaBed 3030 will allow us to finally learn more about the ocean floor. Who knows what we’ll find?