[intense music]
- Tonight, the search for one of the most terrifying creatures
said to prowl the open seas.
- Stories of the Kraken have been around
for centuries.
- It was the size of an island
and its sole purpose was to feast on human flesh.
- There are countless alleged encounters
between sailors and the Kraken,
but descriptions of this creature vary wildly.
- There were tentacles coming out of the water,
wrapping around people,
pulling them back into the ocean.
- All they saw was rapidly moving water,
a vortex that was getting bigger,
and that adds to the mystery.
- Now, we explore the top theories
surrounding this fearsome creature.
- He says, "I have found proof that the Kraken is a real beast
and did exist about 200 million years ago."
- Every time we go exploring in the deep sea,
we find new creatures, and some of them are big.
- With that much isolation and open ocean,
you can imagine that
sailors would start to kind of lose their grip on reality.
- Could the legendary Kraken possibly be real?
[epic music]
- [Laurence] As long as people have sailed the open seas,
[thunder crashes]
they've told tales of encounters
with deadly, man-eating sea creatures.
- Both Jewish and Christian texts reference the leviathan,
which is a giant sea creature that was incredibly dangerous
and eventually killed by God
so that they would not reproduce.
- In the epic poem "The Odyssey,"
Homer describes a deep-sea beast with six heads
and triple rows of teeth that devours passing sailors,
including half of Odysseus's men.
- All cultures that have grown up
along the oceans or the seas
have tales of massive sea animals.
That's why from the 10th century to the 17th century,
maps had all of these sea monsters drawn
and written around the sides.
If you stay within this, you're going to probably be okay,
but if you go out, you could run into something
that could literally swallow your boat whole
and drag you to the bottom of the ocean.
- [Laurence] But over the centuries,
arguably the most feared sea monster of all
becomes known as the Kraken.
In 1180, writings from a Norwegian ruler
placed the beast in Scandinavia.
- King Sverre specifically warned people
against this monster that was menacing ships
between Norway and Iceland,
and he tells us it was the size of an island,
and its sole purpose was to feast on human flesh.
- Later on in the 1500s,
an archbishop named Olaus Magnus
describes the Kraken as having long horns
and built thick like a tree with fiery red eyes.
And this is based on accounts
that he's heard from sailors
whose ships have been attacked at sea.
This is an animal that will sink your ship.
- After the invention of the printing press ,
this description gets distributed far and wide
and is taken aboard ships
that are bound for destinations
like China or even the West Indies.
- [Ryan] Naturalist Pierre Denys' illustration
of the Kraken is arguably the best one of all time
because you have a British warship
being attacked by this massive beast
with all of these tentacles
and it appears to be winning,
so you have to go out there knowing
that this thing could, at any point, take you
to the bottom of the ocean.
- [Laurence] These stories aren't just
centuries-old fables.
Such alleged attacks also occur in modern times,
including one harrowing encounter during World War II.
- [Kavitha] In 1941, the Germans attacked
a British steam liner, the SS Britannia,
just about 750 miles off the coast of Sierra Leone.
Hundreds of passengers are forced to abandon ship
in just a handful of lifeboats, and they're cast adrift
for several weeks, if not months.
- [Ryan] So you have people hanging over the side
of these lifeboas, waiting to be rescued.
Now during this journey,
one of the men on the boat says they were attacked.
There were tentacles coming out of the water,
wrapping around people, injuring them,
or pulling them back into the ocean.
He says, "I was attacked as well,"
and he actually watched an Indian servant be pulled down
with these thick tentacles and devoured.
- This sounds like a tall tale,
but 15 years later,
the eyewitness shows the circular scars on his leg
to a marine naturalist,
who confirms that it was caused by the suckers
of an animal more than 20 feet long, just like the Kraken.
- [Laurence] More than a thousand years
after it first appears in written records,
the Kraken remains a mystery.
What could this terrifying monster really be?
- The thing that the Kraken is most known for
is its massive tentacles.
And there are animals in the sea today
that have tentacles, and they're called cephalopods.
- [Lynne] Typical kinds of cephalopods in the ocean
are just not nearly on the scale of the Kraken,
and in fact, there's really only one potential sea creature
that would even come close to that size.
[tense music]
In the 1850s, a Danish zoologist
by the name of Japetus Steenstrup
is gathering information about these different types
of documented giant creatures,
one of which is the sea monk, which is this large creature
purportedly resembling a monk or a friar,
and these red, flowing robes
that sort of hang in sheets off of his body.
- And as he continued to look at these accounts,
he came up with a scientific description of this monster,
which he called Architeuthis Dux, the giant squid.
This is the first time
where we have a scientist formalizing a description
based on these historical accounts of the Kraken.
- [Laurence] Later in the 1800s,
evidence supporting his theory begins to emerge.
- [Peter] In 1875 in St. John's Newfoundland,
there is an attack of a small boat by a giant squid.
And what's really stunning
isn't just the description of the attack,
but that the sailors, in an effort to save themselves,
grabbed an ax and hacked off a limb.
- The creature slides off into the water and disappears,
but now they have evidence.
One of the tentacles that they have in their boat
is 19 feet long.
- If you were a sailor
and you didn't know the proportions,
you could easily imagine that this was only a tiny fragment
of an even more massive beast.
- Around the time of this encounter in 1875,
full giant squid carcasses
begin washing up off the shores of Newfoundland.
This is the first time that zoologists have an opportunity
to study an intact giant squid.
It features a body which is also called a mantle,
eight shorter arms, two very long feeding tentacles,
and what might be the most fearsome part of this creature,
its mouth or beak.
- By the early 1900s, the scientific community
finally has to admit that Steenstrup was right,
that there is a giant sea beast at the bottom of the ocean
that could be the Kraken that everybody's talking about.
- [Laurence] Unfortunately, live giant squid
prove to be elusive creatures.
Decade after decade goes by without any sightings.
- It's not until 2004 that a living giant squid
is spotted in its natural habitat,
and this happens about 600 miles off the coast of Tokyo.
A marine team has been tracking
what they believe to be a giant squid
using a baited line to try to lure it to the surface,
and on their hundredth dive,
they finally capture it on camera.
- [Ashley] And now, because it's 2004,
we're not talking about the world
of ancient mariners in Denmark
writing letters to each other.
This became a worldwide sensation.
- The world has the first image of a living giant squid.
And watching the animal in its natural environment
answers at least some questions about the Kraken legend.
First of all, the creature's deep-sea habitat
helps explain why encounters with it
have been extremely rare
and the power of its large black beak,
now seen in action by scientists,
jives with descriptions of the flesh-eating monster.
- [Ashley] That beak, which of course has evolved
for catching prey in the deep sea,
is strong enough to sever a steel cable.
- [Laurence] The question remains
whether giant squid grow large enough
to take down ships or devour humans,
as in the Kraken legends.
- [Peter] The squid that was seen off the coast of Japan
was a juvenile,
and while it gave us a sense
of what these squid looked like when they're swimming
and how they position themselves,
there's still a lot that we do not know about the adults.
- If the complete length of a giant squid
is something like 50, 60 feet,
compared to even the largest things in the ocean,
in terms of length and almost in terms of weight,
these are truly large animals.
- [Laurence] But is it possible
for giant squid to grow much larger,
to mammoth sizes we've yet to document?
Some marine biologists say yes.
- There has been this idea of deep sea gigantism
that sometimes at deep depths in the ocean,
things are able to achieve a larger size
than they do at more shallow depths.
- Scientists have studied this phenomenon for decades
and we know that as we look at creatures
that live in the deep dark ocean,
some of them reach extraordinary sizes
because it helps them get around the deep sea
and find what little food there is.
- One reason that we postulate
that the giant squid don't come to the surface very often
is because the amount of energy it would take
to rise up from those deep, cold depths
would be too much of a caloric intake.
- These creatures are certainly not going
to be comfortable living at a higher level,
so it makes sense
that sightings would be incredibly rare.
- [Peter] We know that there are giant squid
that are close to 60 feet,
but could they actually get to be
100 feet, 120 feet?
We don't yet have the answers,
but I think the more we look, the more likely we're going
to encounter these giant creatures lurking in the deep.
- For centuries, sailors in and around Scandinavia
talk about deadly encounters with a Kraken,
a sea creature some experts believe matches the giant squid.
But is that the only possibility?
- Some stories of the Kraken actually have features
that don't match well with the features of cephalopods.
Some have enormous size but are relatively flat in shape,
and it leads us to ask the question,
what other things might have been referred to as the Kraken?
- In 1765, one sailor describes seeing a Kraken
as an enormous fish, but with tiny eyes and fins,
so we're not always talking
about something that can be explained
by the existence of the giant squid.
And some scholars have actually suggested that it might instead
share more characteristics
with a different type of marine animal.
[tense music]
- Whales are enormous
and it's hard to fathom how big they are
until you're alongside them.
When those whales feed, it's loud and boisterous
and it is a sight to behold.
And the cool waters of Scandinavia
are home to many whales
because that's where their food is.
- These whales existing in that environment
tend to be a little bit larger.
I mean, you have humpback whales at almost 60 feet.
You have sperm whales, almost 70 feet.
You can see how these sea animals
could inspire the Kraken mythology.
- Whales are the largest creatures that have ever lived.
Imagine that you're out at sea
and something strange rolls across the surface
and all you see is a dinner-plate-sized eyeball.
That looks like a sea monster to you.
- So there's a real instinctive fear
simply encountering that size of creature,
who, for the most part, is really not interested in us.
But there was one instance off the coast of Ecuador in 1820
when the whaling ship, the Essex, was attacked by a whale
that it had been attempting to harpoon,
and the whale rammed into
the side of the ship and split it into two.
- The story of the Essex was widely reported
after the few survivors came to shore
and was a major influence, we believe,
in Herman Melville's writing of "Moby-Dick."
- After the destruction of the Essex,
that kind of helped stir the lure of giant sea creatures
that are powerful enough
and mean enough to take out an entire ship.
- [Laurence] In 2024, a much smaller fishing boat
off the coast of New Hampshire
is slammed by a breaching sperm whale.
- The sperm whale body checked a small boat.
The whale didn't pursue the boat
or try to damage it any further.
I think it probably was just as confused as the sailors.
- Nobody dies in this case, thankfully.
The ship is flipped, the people take a dive off of it
and are rescued by two other fishermen.
- [Laurence] There is one whale species so enormous
that any encounter could easily destroy a fishing boat
and kill everyone on board.
- Blue whales are unbelievably huge organisms.
They can grow to over 100 feet long
and weigh more than 200 tons.
To put that in perspective,
the largest dinosaurs ever weighed about 65 tons.
- If you had not yet seen a whale,
or even if you had seen a whale and not seen a blue whale,
the scale difference there
is enough to really make you question what you had seen.
- Even though blue whales feed on krill,
which, tiny little marine animals,
the odds of them swallowing a human
or going after humans is almost zero.
But somebody could have just happened
to be in the wrong place at the wrong time
and, boom, swallowed completely.
- [Laurence] It's hard to imagine
this happening in real life,
until a marine biologist claims he was swallowed by a whale
and has the pictures to prove it.
- [Ashley] In 2019, Rainer Schimpf was taking photos
on the coast of South Africa
when he was swallowed by a massive whale.
He spent about 30 seconds in the mouth of this whale
before being spit back out, but he made it through unharmed.
- No one would've ever believed him.
It would've been just a big fish tale
if it wasn't for his wife,
who was standing nearby
and snapping photos of the whole incident.
- If that story weren't enough,
we have further accounts.
In 2025, off the coast of Chile,
a man kayaking is caught on camera
in the moment that a whale rises up from beneath him
and scoops him up entirely.
- He was quickly spat back out
because whales do not eat people.
But if you're in the wrong spot,
even if you're in something as large as a kayak,
you might get swallowed by a whale.
- Even if these encounters with whales
that led to them being engulfed are harmless,
witnessing or experiencing something like that
could easily contribute
to the myth of the man-eating Kraken.
- [Laurence] Is it possible a whale
might be mistaken for a Kraken,
not just at sea, but on dry land as well?
- Unless you understand anatomy,
if you encounter a decomposing animal,
particularly a sea creature on the beach
that's getting reworked by the elements,
it might be very hard to identify what that creature is.
- In 2017, a strange, misshapen carcass
washes up off the shores of the Indonesian island, Seram.
Photos of it
immediately go viral worldwide.
It's 50-feet long, bloated,
and unlike anything that's ever been seen before,
- People are talking about weird fur on it
and that there's this red liquid nearby
and they're just baffled.
So it's easy to understand how they could have thought,
"This is the Kraken."
- Many cases of unexplained animals
or unexplained carcasses
have very poor quality documentation,
but eventual testing of this revealed from DNA
that it actually was part of a baleen whale.
What was initially thought to be fur
was actually the structures within the whale's skin
as it falls apart.
The red fluid was eventually identified as whale blood.
- [Laurence] For centuries, people have been searching
for evidence of the giant sea monster known as the Kraken.
Marine biologists have compared it
to whales and giant squid,
but neither seems to be a perfect match.
- What if there is something else out there,
an unknown sea animal that
we just haven't been able to capture yet?
- Scientists pretty much dismiss this idea
that it could be its entirely unique species
until a group of fishermen in the 1970s
haul in something truly unexpected.
- In 1977, a Japanese fishing trawler
was able to pull in this massive carcass.
This thing was 30 feet long and 4,000 pounds.
- This is truly something they have never seen before
and cannot account for.
It appears to have an incredibly long backbone.
It has these four sort of strange fins on it,
but because it smells so atrocious,
they all decide to toss it back in the ocean.
- Luckily, somebody snapped a couple of photos of it
and actually took a sample,
and they sent that sample away to get it tested.
Now what's interesting is,
normally a sample comes back
and you're like, "Oh, blue whale."
This came back inconclusive .
- Based on photos, based on the description
that the fishermen were able to give,
the official interpretation that the government makes
is that this was likely a decomposing basking shark,
so it's one of the largest creatures there is.
They grow up to about 30 feet long.
- [Laurence] But another Japanese scientist
has a much more controversial theory.
- Professor Tokio Shikama of Yokohama National University
believes that the carcass
is actually the remains of a dinosaur,
specifically the plesiosaur,
which was one of the deadliest beasts to ever roam the seas.
Some descriptions of the Kraken
do fit with certain aspects of the plesiosaur.
So if the dinosaur had managed to survive to modern times,
as Shikama maintains,
that would mean that the origin of the Kraken
actually goes back millions of years.
[tense music]
- Plesiosaurs are large, aquatic reptiles
that lived during the time of the dinosaurs.
They lived in the Cretaceous Period.
- These creatures are the T. rex's of the ocean,
big giant animals with extraordinary teeth
that were voracious hunters.
And they've been extinct for some time.
But this professor said,
"Well, this could well be a plesiosaur
that we just have never caught before."
- [Laurence] If this creature is a survivor
from the age of dinosaurs, then it rewrites everything
we thought we knew about their demise.
- Most scientists agree that
there was a mass extinction event
about 66 million years ago
when this asteroid, six to nine miles wide,
slams into the Yucatan Peninsula with such power
that it drives itself 14 miles into the Earth.
- When you have an asteroid that is this size,
you have boiling oceans,
you have pure darkness that takes place,
and also displacement of a lot of water,
so it wiped out 75% of the Earth's species.
And for the animals that dwell in the water,
this was the apocalypse.
- [Laurence] Yet some theorists counter
that an asteroid strike in the Yucatan,
no matter how destructive,
wouldn't wipe out all the dinosaurs around the world.
Some, they contend, could survive the cataclysm.
- The Loch Ness Monster is arguably the most famous
possible plesiosaur in the world,
and Loch Ness is connected to the ocean,
but so far away that you could theorize
that if they were inland when this happened,
they would've been saved from this catastrophe.
- [Kavitha] It's interesting to note
that Loch Ness does connect to the open ocean,
the North Sea, which then connects to the sea of Norway,
and all of these waters surround Scandinavia.
- [Ryan] The Loch Ness Monster has gathered
decades of attention, but until they find a body,
there is no way to prove
that the Loch Ness Monster or a plesiosaur
is what is actually the Kraken.
- [Laurence] There are other formidable predators
thought to be long extinct
that share similarities with the Kraken.
One is a giant fish
that cruised the seas for a million years.
- There are some Kraken descriptions
that talk about a long, sleek fish with massive teeth,
and this has led many to think that maybe,
that's evidence that megalodon still lives.
[tense music]
- [Ryan] We have great white sharks
which can grow up to about 20 feet in length,
and the megalodon was two times the size of the great white
or maybe bigger,
the largest fish ever to exist.
- [Lynne] It is believed to have gone extinct
about 3.6 million years ago,
but of course, similar to the plesiosaur,
there could have been
some that survived down in deeper water,
still living in the oceans today.
- Most scientists think this is highly unlikely
because no bones or teeth of a megalodon
have ever been found on the ocean floor
that weren't fossilized.
But some theorists wonder if maybe a few megalodons
actually did manage to survive into the modern era.
- [Laurence] It might seem farfetched,
but there are other examples
of prehistoric beasts surviving the asteroid impact
that have been verified by scientists.
- [Ryan] In 1938, a South African fisherman catches
something that he's never seen before.
It has these armored, blue scales
and its fins aren't normal like fish fins.
They're actually fleshy.
- So he sends this off to a marine biologist
who absolutely cannot believe what she's seeing.
It's called the coelacanth,
but the most recent one was from 66 million years ago.
- The news of this is so startling, it's a bizarre animal
and maybe one people hadn't thought of before,
but the resurrection story of it
led to a worldwide recognition of an animal
that was thought to be from the age of the dinosaurs.
- [Laurence] Evolutionary biologists
are faced with a new mystery:
If this prehistoric fish survived the great extinction,
is it possible a beast like the Kraken did as well?
- Perhaps the coelacanth fish survived
because it's relatively small.
It's only six feet long
and weighs about 200 pounds,
so it doesn't require a ton of food.
But for a species the size of the Kraken
to endure an extinction event,
it would've had to have somehow been protected
from all the destruction.
Some wonder if maybe there were sealed pockets
in the ocean floor that acted as safe zones
for colossal prehistoric beasts,
and something later happened to open these pockets
to release one of these beasts into the ocean.
- Could the Kraken be more than a mariner's myth?
Scientists are still trying to find out
whether or not this infamous sea creature is real.
If it is, could it be a survivor from prehistoric times,
something that could grow three stories tall
and crush the skeleton of even the largest predator?
- In 2011, at a meeting of the Geological Society of America,
paleontologist Mark McMenamin presents
a really interesting and controversial idea.
- He says, "I have found something that I believe
is proof that the Kraken is a real beast
and did exist about 200 million years ago."
He was unearthing fossils
in a ghost town called Berlin in Nevada,
and he came across an ichthyosaur,
which we know existed.
- These are almost dolphin-like in shape,
many sharp, pointed teeth in a long snout,
very highly adapted to ocean life,
and the fossils that were found in Nevada
are actually whale-sized.
- What's strange to McMenamin
isn't the existence of the ichthyosaur,
but that when he finds these bones,
he doesn't find just one set.
He finds nine of them, and they're all arranged
in a distinct pattern.
These piles are not the result of nature.
Some other creature had to have placed them there.
- [Lynne] The ichthyosaur would've existed
near the surface of the ocean.
Of course, this is a time
when Nevada was entirely underwater,
so whatever killed them
traveled to the surface of the water,
hunted them, and then brought them down, all the way
to the floor of the ocean to stack their bones.
- If you then take the markings
on the actual bones themselves,
they don't look like teeth marks.
They look like something that a beak would do.
And to pull something of that size down into the depths
and hold it down and eat it,
you would have to be enormous.
So he postulates that this is an ancient giant cephalopod.
- McMenamin is convinced and he keeps digging,
and he finds what he thinks is the jackpot:
a beak, the kind of beak that would have come
from a creature about 100 feet long.
- [Laurence] The giant squid is not the only creature
that uses a beak to tear apart its prey.
In this case, the evidence points more toward an octopus.
- [Ryan] What we know about octopus
is they attack with twin beaks
and they pile the bones of their victims
in front of their lairs.
You know, they use this.
These are traits we know and we have witnessed in nature.
- Today, the largest octopus that we have is
a lot smaller than the largest giant squid that we have,
but it's entirely possible that in the prehistoric eras,
there was an enormous octopus species
that could have survived into modern day
and become what people saw and called the Kraken.
[tense music]
- [Kavitha] During the great extinction,
earthquakes caused massive craters
on the sea floor some many miles deep.
Some species, including octopus, which prefer to live
on the sea floor in spaces like these,
could have found sanctuary in them
and survived the apocalypse happening above.
- Imagine if you had the size, the stealth,
and the intelligence to hunt and stay unnoticed
by not only the predators in the sea,
but the predators from above.
And the one thing we know about octopus
is that they are arguably
the most intelligent species in the entire ocean.
- We know very little about what lives on the sea floor.
You'll hear people say that, you know,
we know the surface of Mars
better than we know the floor of our own ocean,
and that is literally true.
- In 2024 in Norway, scientists have been
discovering these sites called hydrothermal vents
on the sea floor that are just booming with life.
A secret to success are the bacteria
that are able to take the chemicals
that come out of there, really noxious chemicals,
and to eat and to grow off of it, and you end up
with these really lush communities of creatures
all basically living off the energy
that comes out of the inside of the Earth.
- This totally changed the way that we thought about
the domains in which life could exist.
The animals at these deep sea vents
don't necessarily even need sunlight.
If the sun blinked out, the animals at the deep sea
might not know about it for millions of years.
- [Kavitha] Many marine biologists dismiss the theory
of the Kraken emerging
from these deep sea holes
as something out of a Jules Verne novel.
Just because a giant prehistoric cephalopod
might have existed many millions of years ago
doesn't necessarily mean that it survived
into the days of seafaring humans.
- [Laurence] But others say it's not so far fetched.
It's estimated that 2/3rds
of the marine species in our oceans
have yet to be discovered,
and some argue that among them
could be survivors of the great extinction.
- Every time we go exploring in the deep sea,
we find creatures that we had not previously known,
and some of them are big/
So are there monsters lurking in the deep
that we don't know about?
It's possible.
- [Laurence] For centuries, people have been trying
to identify the Kraken
by comparing it to other marine life, real or imagined.
Now, some are asking
if other factors fueled the imaginations of sailors,
especially those heading into the treacherous waters
of the Scandinavian seas.
- One of the descriptions of a Kraken attack
is that suddenly the ocean begins to spin
and it creates this massive whirlpool
that sucks ships down to their graves.
- The churning waters off the coast of Norway do just that.
Their force inspires writers like Edgar Allen Poe,
who wrote a short story about a man who survives a shipwreck
and a whirlpool that he calls a "maelstrom."
- The legends of the maelstroms could well be based in fact.
The Saltstraumen Channel on the Norwegian coast
has terrifying opposing tidal currents.
They can capsize boats, and when that happens,
people can drown and people have drowned there.
It's taken many lives.
- Sailors back then, all they saw was rapidly moving water,
a vortex that was being created and getting bigger.
You might perceive that as a beast
because they didn't know what we know now.
- [Laurence] Could it be that generations of sailors
have been blaming ship disasters
on an imaginary creature, when the sea itself is to blame?
[tense music]
- Most long-lasting maelstroms are not the consequence,
like a tornado, of wind masses,
but actually of convergent currents in the ocean itself
that when they meet at different angles, produce a vortex.
- [Karlene] These vortexes that are being created,
they're moving at a pace of about 23 miles per hour.
They could be about 33 feet in diameter,
and that creates the illusion.
Not only are you out there thinking about a mythical beast,
but you're also seeing some movement in the water.
- [Laurence] It's rare that these whirlpools
are strong enough to pull in entire boats,
unless the circumstances are just right.
- Maelstroms are especially dangerous
when they have a deep hole at the bottom of the water
that acts like a drain speeding up the flow.
- One incredible example of this
is something that happened in 1980
in Louisiana's Lake Peigneur.
In this lake, there's two activities going on.
One is a salt mine being dug out underneath the lake,
and one is an oil rig.
And due to an accident of calculations,
they end up drilling
into one of the lower shafts of the salt mine.
- And as they're drilling, they hear a couple of loud noises
and then the water begins to spin around the rig.
The lake is only 10-feet deep,
but what happens is they created
the hole needed for the water to go into the salt mine,
multiple levels, thousands of feet down.
In seconds, it sucks a tugboat, 11 barges,
an entire island with a botanical garden on it,
into the whirlpool, gone.
Maybe the most incredible thing about it
is that nobody was hurt.
- That was human error.
You're talking about an oil rig
that went right into a salt mine.
That's something that definitely
does not happen every single day,
but we also see these whirlpools
that are created out in the open water
just from naturally occurring events like earthquakes.
- [Lynne] In 2004, off the coast of Thailand,
an underwater earthquake caused a tsunami so large
that the loss of life topped 200,000 people.
And in 2011 in Japan,
a similar tsunami took out 19,000 people
and the entire Fukushima Nuclear Plant.
- In both instances, the first to succumb
are people sailing near the quake's epicenter.
Before a tsunami rises up from the displaced tectonic plates
and hits the coast, there are several moments
when water fills inside the enormous cavity,
and in that case, boats as far as 10 miles out
can be sucked into this giant whirlpool
that's been created by the cracks in the sea floor.
- [Laurence] In such events,
it's possible sailors might have confused
a natural maelstrom with the Kraken's attack.
- You have to ask,
how many times could this mistake have been made?
How many times could someone have seen
a natural phenomenon like this
and attributed it to this monster?
- [Karlene] If you're already going out there
with the notion that there is a beast in the water
and you continue to see the whirlpool getting bigger,
you're gonna think that the beast is
about to jump out of that wate,
and you're about to be face to face with the Kraken.
- [Laurence] Many theorists have turned away
from trying to link the Kraken to a living creature.
Some now wonder if
the psychological effects of sea travel
gave rise to this legendary beast.
- You have to think about the conditions that
sailors live with, especially hundreds of years ago.
A lot of sailing voyages
could be up to three years at a time,
and with that much isolation and open ocean,
you can imagine that sailors
would start to lose their grip on reality.
- We walk on land, we live on land.
To remove you from that
is something that you have to experience to understand.
It begins to immediately play with your mind.
- Some experts have theorized
that the stories that are told about the Kraken
aren't the result of any actual creature in the ocean,
but instead are a sign of the psychological impact
that being on the ocean has on the crew.
[tense music]
- You can imagine how terrifying it is
to go to sea in an old, rickety sailing ship
with no GPS, no weather forecast,
and you probably don't have much of an education,
certainly not in zoology.
- Many sailors in the past couldn't even swim,
and so anything that happened
beyond the bulkheads of a ship
was often misunderstood.
- These sailors are dealing with stress and storms,
cabin fever, and obviously heavy drinking,
and all of these things can actually affect
whole crews at the same time.
It's called mass hysteria,
a phenomenon where a group of people
can experience similar physical or psychological symptoms
without a singular, identifiable medical cause.
- In 2024, the U.S. Navy did a really interesting study
and found that 41% of sailors going to sea
suffer a form of high stress before getting on the boat.
Let's go back hundreds of years ago
and you're about to head off into sea,
and the only thing you know is that there is
a Kraken out there waiting for you.
Tell me that your stress levels wouldn't be through the roof.
So these sailors weren't just battling sea monsters
and crazy environmental problems,
they were also battling themselves.
- [Laurence] Diseases at sea can also induce hallucinations.
- Another big component back then was scurvy.
And so scurvy is a lack of vitamin C,
and that deficiency is a horrible way to go.
You're talking about your arms
as well as your legs being sore and then stiff,
you have your teeth falling out, your gums are bleeding,
and then eventually it makes its way into your brain
and causes damage.
- Under the stresses of scurvy,
sometimes the senses become changed,
and in the 1740s, an entire squadron
of British sailing vessels was overcome with scurvy
and their sailors reported strange sounds,
exaggerated sights, and one famous report
was of a man who the simple smell of a flower
was enough to make him scream in agony.
- According to one historian,
scurvy is responsible for more deaths at sea
than storms, shipwrecks, and other diseases combined.
And it was not a quick death.
It could take weeks for people to die of scurvy.
- You're in this mental state because of scurvy,
your brain is deteriorating,
so what you think you saw
might not actually be what is out there.
- [Laurence] Hallucination brought on by
psychological stress, fear, and disease
might be a convincing explanation
for stories of the Kraken,
but it's not the only way the brain might trick us
into believing there are strange creatures nearby.
- For folks who spend time at sea,
you realize very quickly that your eyes can deceive you.
The fact that you don't have a frame of reference
when you look out across the ocean
means that things can seem grander
and larger than they appear.
[tense music]
- [Karlene] Atmospheric factors play into this.
You have the cold air that's closer towards the sea level,
the warm air that's rising over it.
Once that light moves from cold air into warm air, it bends,
and so that changes
what you are physically seeing out in the distance.
The flying mirage illusion
can make it look like a boat is in the air
because of the way that the light is bending,
so your perception is off,
and that creates a bigger story
when it comes to creatures
that are out there on the open water.
- Even real objects perceived
with these atmospheric conditions
can be elongated, stretched, or bent
in ways that might make them appear monstrous.
- [Laurence] Could phenomena like these
have contributed to Kraken sightings?
- At the end of the day, the oceans are not our home.
That is not our natural environment.
So I don't care how brave you are
or how prepared you are, you're going to step off
into that adventure with a little bit of apprehension.
- Stories of the Kraken have been around for centuries,
and even modern discoveries
don't fully explain where they came from.
- [Peter] History is replete with stories
of sailors talking about creatures trying to kill them,
and if you take a look at them,
you begin to see that those monsters
probably tell us more about us than anything else.
- It may be tempting to dismiss the Kraken
as the world's oldest maritime legend,
or the product of sailors' minds playing tricks on them.
But if so, then why does the Kraken still fill us
with fascination and fear?
With as much as 80% of the ocean still unexplored,
discovering a sea monster
that truly lives up to the Kraken lore
may just be a matter of time.
I'm Laurence Fishburne.
Thank you for watching History's Greatest Mysteries.
[dramatic music]