40 Eerie Sea Photos That Might Give You Nightmares Tonight

The ocean is a beautiful and mysterious place filled with creatures that have yet to be discovered and studied. Not knowing what lies beneath also makes the sea a terrifying place to be in. The ocean is full of never before seen beings that could be the stuff of nightmares.

While some see the depths of space as the final frontier, it’s worth remembering that humans know so little about the furthest reaches of the ocean.

If you are ready to see the amazing creatures that lie underneath the vast blue sea, prepare to be surprised, shocked, and awed!

The Ocean Has Eyes

What would you do if a slew of spooky eyes were looking at you from the surface of the dark sea? Would you run, pray, or scream? Relax. Those are merely alligator eyes looking at you in the middle of the night. You are 100% safe as long as you don’t go swimming. Or hang out near the water’s edge. On second thought, maybe it’s not safe after all.

Alligators have the ability to swim at a speed of 20 mph. Plus, their jaws could easily clamp anything and anyone that weighs more than 2,000 pounds. Essentially, you’re safe as long as you get out of their way and avoid being dragged as underwater prey and succumb to its “death roll”— a strategy where they tire their victim prior to tearing off their limbs.

Parasitic Bloodsucking Creepy Eels

Eels that can suck all the blood out of you also live underneath the sea. New Zealand’s Te Papa Tongarewa museum captured an image of these parasitic eels via their YouTube video titled Living on the Ocean Floor. These eels were seen 880 meters below the ocean’s surface. When they all group together, they look like a giant sea monster surrounded by slimy arms.

These creepy eels can attach to their prey and suck their victims’ blood using their sharp teeth and disk-shaped mouth. If their mouth alone doesn’t send shivers down your spine, we don’t know what will.

Octopuses Never Waste Opportunity

If you think this picture of a large number of octopuses looks scary—you are correct. They are actually eating the remains of a humongous whale. Not only is the whale’s skeleton creepy, but the octopuses are also tearing every piece of the whale’s flesh off bit by bit.

The creatures are making sure nothing is left of the marine mammal. Though octopuses are predators, they do not shy away from taking any “free lunch” eating opportunity that comes their way.

Chased By Killer Whales

Just when you thought nothing was better than a peaceful kayak trip, a fin from the depths of the sea pops out to say “hi.” Fortunately, it’s a bit far from where you are. Unfortunately, it’s coming towards you at lightning speed.

Thankfully, the creature is only a killer whale. Despite its name, this whale does not kill people. So you can continue kayaking in peace. As peaceful as you can feel out in all that water with such an enormous animal on your tail. 

Big-Mouthed Monster

The basking shark is the world’s second-largest fish. Adult basking sharks have been known to grow up to 26 feet. Despite their scary size, they do not eat humans. However, they do have enormous mouths. It is best to stay away from them if they are feeding as they could easily swallow anyone whole.

They use their large mouths as a filter feeder. Essentially, they consume zooplankton by swimming toward them and sucking them in with tons of water. The water is eventually filtered through the grills in their mouth while their prey is digested.

Courageous Cave Diver

One of the reasons why a lot of people are afraid of the ocean is because of its size and seemingly limitless depth. Most of its areas are largely unexplored. However, that didn’t stop this scuba diver from going where no one had yet gone before.

The darkness and the possibility of getting stuck inside the cavernous pitch-black hole were not enough to keep him from going through his under-the-sea cave adventure. Thanks to his courage, we now know what a sea cave looks like—but we wish we didn’t.

Jesus Is Everywhere

Jesus isn’t just omnipotent—it seems he is also ubiquitous. He can be anywhere and everywhere he wants to be. It is, therefore, no surprise to find him in the ocean, just in case you are looking for some ocean-deep wisdom and guidance.

This bronze statue of Christ was actually created by Guido Galletti. It is but one of many statues that were placed in numerous under-the-sea locations in different parts of the world. This specific statue is in Key Largo, Florida, and weighs 600 pounds. 

Anaconda’s Day Out

If you have a snake phobia, we recommend that you do not look at this picture of an anaconda swimming near a submerged train. We are not sure if this creature was curious to see a train underwater or if it was actually hunting for prey.

And speaking of snakes and prey—anacondas can actually swallow theirs whole. They can also grow to as much as 29 feet and weigh more than 500 pounds. Again, just for comparison, check out the size of this snake when compared to an old-timey train.

Frozen Underwater Ship

There’s something so hauntingly beautiful about this shipwreck. This boat was found in Antarctica after it sank. At that time, a Brazilian journalist named João Lara Mesquita was shooting a documentary with his crew when strong winds, as well as stormy seas, caused them to abandon ship.

Fortunately, they were rescued. However, water eventually washed over the ship, and it froze. The boat has since remained underwater in this state ever since. The sight of it is enough to elicit numerous ghost stories, no doubt.

The First Underwater Portrait

It might seem hard to believe, but this image is considered the very first picture ever taken underwater. This photo is of oceanographer Emil Racovitza and was snapped (or rather, slowly captured) in France by Louis Boutan in 1899.

The picture was taken under a depth of 164 feet. Oceanographer Racovitza and photographer Boutan took thirty minutes to capture the image because they needed to wait for the perfect quantity of light to capture the image.

Hole In Alaska

There is a hole located at Alaska’s Lower Ruth Glacier that seems to go on forever. Fortunately, it doesn’t. Unfortunately, no one really knows what lies at the hole’s depths. No one can determine how far it goes, either. Some say it ranges anywhere from 300 to a thousand feet.

Also, the hole is exposed and not covered—only a thin sheet of ice covers it. It is easy to fall right through. The hole is filled with ice water, making it extremely cold. As if this icy drop weren’t dangerous enough!

Shipwrecked 1800s Merchant Vessel

This old ship was found at the depths of the Mexican gulf during a routine ocean exploration. It was a remote-operated vehicle of the National Oceanic and Atmospheric Admiration that made the discovery. Aptly named Deep Discover, the vehicle was originally used to extract samples from the deep recesses of the ocean, approximately 3.7 miles below the surface.

The vehicle took many pictures, then converted them into a 3D mosaic survey. The resulting image was a shipwrecked merchant vessel from 1830. It’s incredible what remains hidden deep below the ocean surface. Imagine what else there is to find there.

Seaweed Monsters

This image is another reason why many are fearful of the ocean. The black tendrils behind the curtain of waves look like sea monsters. However, they are nothing more than seaweed. Either way, it is still a terrifying sight.

Though they are just bits of seaweed, they can still be dangerous. Anyone can easily be tangled in them, pulled to water, and drowned. Surfers should be very careful if they spot them while catching waves.

Meet Sea Dumbo

If you think Dumbo is cute, prepare to meet its under-the-sea version. This Dumbo-like octopus is actually named after the Disney character. It’s easy to see why. It’s adorable for a deep-sea creature!

The sea dumbo is not your usual eight-tentacle octopus. It is adorable and cute and is not a threat to humans. Its ear-like fin extends from the mantle above its eyes and is what the dumbo octopus uses to move. They live far deep in the ocean and are seen more than 13,000 feet below the surface.

Large Dangerous Swells

It’s not just scary monsters or mysterious shipwrecks that make the ocean a scary place. The sea is also terrifying because of its powerful waves. As you can see, Portugal’s Nazare coast is very much exposed to the ocean's destructive power.

Nothing can slow down or stop the swell from reaching the coastline. Surfers consider this area the perfect place to ride the waves and even make world records—but they do so at great risk if the waves are surging.

Attack Of The Sharks

Sharks are the sea creatures that scare humans the most. Though they have long occupied everyone’s minds as a notorious ocean predator, they rarely attack humans. Instead, sharks prefer eating marine animals over people.

However, these facts do not mean you should let your guard down. Sharks eat humans relatively less. Great white sharks are largely responsible for unprovoked—and at times fatal—attacks on humans. 

Frightening Fish

We bet you haven’t seen a sea monster that resembles an alien creature like this one. A video from YouTuber Distort303 titled Taenioides revealed a fish from the gobies genus, which is usually seen in brackish, fresh coastal waters.

The eyes of the creature are small and almost nonexistent. To compensate for its tiny vision, it has sharp teeth to easily capture its prey. Given that it lives in the darkest depths of the ocean, sightings of this sea animal are very rare.

The Devil And The Deep Blue Hole

There is no demon or evil spirit in this picture, but it still seems as though evil could be lurking within the depth of this blue hole. The person swimming in this image while wearing no diving gear appears to be heading into nothingness.

Is it safe to dive into this abyss? Surely it is not. We suggest that you do not try this on your own, even if you feel you’re up to it. Maybe bring one of those pressure-proof submarines, and a bunch of underwater torches—as many as you can carry, in fact.

Poisonous Fireworm

Just when you think the ocean couldn’t be scarier, along comes sea creatures that could strike fear into the heart of any living being. This man is showing off a bizarre sea animal called a bearded fireworm, a specific kind of marine bristle worm.

This fisherman was expecting to catch bass; instead, he captured this unique beauty-come-horror. We hope this guy was extremely careful as this type of fireworm is poisonous to the touch. That’s one beard we really don’t want to stroke.

Jaws Week

This chilling image is enough to instill a sea and shark phobia in anyone. Imagine if that shark’s face was looking at you from the surface of the water. Would you be able to sleep at night? Would you ever be able to dip an ankle into seawater ever again?

Sharks can grow to as big as twenty feet, and they weigh more than 5,000 pounds. Fortunately, sharks do not prefer humans as prey. Instead, they like to eat huge animals. That being said, no one wants to swim with these guys. You’ll never know when they get hungry.

Beautiful Jellyfish

While this jellyfish doesn’t just look scary, the thought of its stings should frighten you. The possibility of seeing one at the beach is enough to make you avoid swimming. The lion’s mane jellyfish is so large it eats smaller jellyfish.

Despite their ability to sting, their colors and appearance are gorgeous. This jellyfish got washed ashore on Northumberland Beach in England, and its beautiful but tragic image was captured for posterity.

Ocean Bugs

Though this looks like a pill bug, this creature is a large isopod that can usually be seen in cold climates. They are perfect examples of deep-sea gigantism, wherein the deeper any creature lives in the sea, the bigger they become. These bugs can get as big as twenty inches.

Fortunately, these isopods do not bite and are not a threat to humans. Still, they look creepy. But they could actually be eaten, and those who have consumed these bugs describe their taste as similar to crab and shrimp.

This Creature’s Real Name Is “Sarcastic Fringehead”

Sarcastic Fringehead seems an apt description for this saltwater fish, and as such, that was how it was named. Just like its namesake, it is very aggressive and territorial. Anytime two of these fight, you will see them wrestle each other by pressing their mouths against each other.

They may look like they are kissing, but they hate each other’s guts. The Sarcastic Fringehead can usually be found in the Pacific off the North American coast from California to Baja. These creatures can grow to as much as 12 inches in length. 

Kayaking With Blue Whales

We are unsure if the people in the kayak were aware of the majestic blue whale swimming underneath them in this image. One sharp move from one of the world’s largest mammals could have sent the kayak and its passengers flying off to the Pacific Ocean.

The blue whale can grow up to almost a hundred feet in length and weigh 200 tons. This is roughly equivalent to 400,000 pounds. The weight of a blue whale’s tongue is equal to the weight of an elephant. Plus, their heart weight is similar to that of a car. Despite their intimidating size, they do not harm people and only eat krill. Unfortunately, many of them die each year because they collide with large ships.

Shark Surfing

Seeing a shark while out surfing is the stuff of nightmares. The Jaws movies clearly didn’t help their reputation as lean, mean, human-eating machines. They may look scary, but humans aren’t their usual prey. Statistics from the International Shark Attack File show that there are only four annual fatalities worldwide due to unprovoked attacks.

The best way to not catch the attention of these creatures is to avoid wearing anything metallic or shiny. Also, do not splash around in the water too much. In general, it’s best to research the beach you are staying at to check if any sharks have been sighted there.

What Lies Beneath?

This picture could pass off as a movie poster of a scary sea monster. But this is a real image of a “fish of 10,000 casts”. The name describes the largest marine member of the pike family. This monster measures 24 to 48 inches in length and weighs anywhere from 15 to 36 pounds.

This creature is called a musky—or muskellunge, to give it its scientific name. There is a reason to be scared of them as they do tend to attack humans, albeit rarely. Seeing this in the water might be enough to give you a heart attack.

Hammerhead Shark Week

As if there weren’t enough sharks on this list, here’s another shark-related item. Specifically, these are hammerhead sharks. They are named as such because their head structure resembles a hammer. These sea creatures could grow to 20 feet in length and weigh a thousand pounds.

Relative to their shark relatives, hammerheads are smaller and do less harm to humans—but that’s no reason to treat them as cuddly pets. Still, seeing them together in the ocean could probably elicit a panic attack.

Gulper Fish

This sea creature is called a pelican eel. It is also referred to as a gulper eel because it consumes its prey by gulping it whole. Thanks to its large mouth, it also gulps in water and expels it via the slits on its gill.

This photo does not do justice to the pelican eel’s skill of blowing up soap bubbles in its mouth and having it expand to insane proportions. Better that you don’t see—perhaps it will preserve the little sleep you will get tonight.

Underwater Stargazer

It is difficult to imagine that a northern stargazer is a sea creature, not a heavenly body or telescope. It’s the name of a fish that could weigh anywhere from 6 to 13 pounds. Its length has been known to extend to 22 inches.

The sea creature’s name is based on its eyes as it sits atop its head. It burrows itself under the sand and pokes its eyes out from under it. This fish can be seen along the Atlantic shores, specifically in New York and North Carolina.

Dory Has Been Found

This is a real translucent fish and is still a baby. Referred to as a larval surgeonfish called a blue tang, once it grows up, it will look like Dory—the fish from the movie Finding Nemo. The blue tang can grow to 12 inches. As an adult, it has a royal blue body and a yellow tail.

The reason for the fish’s translucence is its built-in defense mechanism because a larva is defenseless as a baby, and being transparent helps them hide from predators. It’s not just Nemo doing the hiding!

Close Encounter With A Shark Kind

The fin sticking out of the water is actually a shark. The way that the sea creature is so near the surfer is enough to scare anyone. Mick Fanning, the guy in the picture here, was almost attacked by the animal.

Fortunately, Fanning was able to fight the creature off. He managed to escape the attack of the great white shark during South Africa’s J-Bay Open surfing competition. He was fearless, no doubt, and there is an additional photo of how close he was to being shark food.

Surfing Shark Partner

Swimming with a great white shark is dangerous because it is considered one of the most terrifying predators in the ocean. But that is what surfer Brad Coder did when he was in Queens, New York. He only realized he was swimming with a dangerous shark when he watched his GoPro.

He was casually sifting through the video footage when he saw he was not alone. A shark glided underneath his legs while they were dangling off his surfboard. We’re not sure if that makes it better or worse.

Poisonous Portuguese Man O' War

This jellyfish is actually not a jellyfish. It’s called a Portuguese man of war or a “blue bottle jellyfish.” Often referred to as a siphonophore, this creature actually consists of a set of separate organisms, all working in unison.

Their tentacles could extend to as long as 165 feet and are extremely poisonous. Fortunately, they are not as deadly though their sting can be very painful. Its sting can affect the lymph nodes and cause shock, fever, and breathing difficulties.

You Have Been Warned

If this sign doesn’t keep you away from the dangerous areas of the ocean, we don’t know what will. This warning can be found at the cave entrance in Florida’s Vortex Spring - a recreational diving area for both experts and newbies.

The sign is also dead serious as 13 divers died during the early 90s when they explored the cave. Florida acknowledged the gravity of the situation that it threatened to prohibit diving anywhere near the cave entrances. Still, some prefer to risk their lives than remain alive. In 2010, an uncertified diver snuck into the cave and was never found again. 

Fear Of Water

There is actually a word used to refer to the deep fear people have of deep bodies of water. The fear is called “thalassophobia,” and it covers anyone who fears pools, the sea, or the ocean. It also includes the fear of the ocean’s emptiness or vastness.

If you have thalassophobia, we guarantee you would be sweating buckets now just by looking at this picture of a person plunging deep into the wide empty ocean space. It’s an evocative image all on its own—but chilling to those with the phobia.

Giant Squid

The Humboldt squid is a force to be reckoned with, land or sea. They were even given the name “diablo Rojo” or “red devil” because they are known to attack fishermen and divers. Once they are captured, the jumbo squid struggles to get free by flashing the colors red and white.

They also grow to a length of five feet and can weigh 110 pounds. They have the ability to move and swim at a dizzying speed of 15 mph. If you see red under the waves, remember you might be tangling with this devil.

The Endangered Gentle Giant

Blue whales are large gentle creatures that are harmless to humans. Despite their 400,000-pound weight and more than 90 feet long bodies, there is no reason to fear them as they are gentle giants.

This diver found it easy to swim with one and probably enjoyed the experience. There used to be a lot of blue whales in every ocean. However, hunting has caused this species to become endangered. Blue whale hunting has been banned since the 1960s.

The Sarcastic Kissing Fish

This image captures another angle of the sarcastic fringehead. Notice its big-sized mouth, which it uses to the hilt when battling it out with another sarcastic fringehead. The fish that has the bigger mouth gets to establish dominance.

The razor-sharp teeth of this fish could be extremely painful. Usually, they hide within shells and even man-made objects such as soda cans. Doesn’t the ocean just produce the weirdest creations out there? 

Spooky Spookfish

There is a reason why this fish is called “spookfish.” Besides its spooky look, it has barrel-shaped eyes that can move forward and upward. Also known as barreleyes, their vision allows them to detect the presence of predators at any angle. In other words, they have supernatural senses.

The transparent heads of these deep-sea fish creatures have the ability to gather even the weakest particles of light. It also protects their eyes from the sting of siphonophores—a creature of which the spookfish steal food items.

Giant Squid

Giant squids are bigger than jumbo squids. These creatures could grow to as much as 33 feet and weigh more than 400 pounds. Essentially, giant squids are another perfect example of deep-sea gigantism, in which the deeper creatures live under the sea, the bigger they get.

Giant squids are one of the ocean’s biggest predators, as evidenced by the scars seen on this whale. Giant squids also have eight tentacles, all of which possess suction cups, which they use to attack prey. Their beaks also have the ability to peck through even the thickest skin.