Divers' Terrifying Encounters with Mysterious Underwater Monsters

Divers often venture into worlds that most of us do not see, taking in vistas of tranquil seascapes and magnificent wildlife, some of it rarely glimpsed. They peek through a window into underwater worlds that lie out beneath the waves of our world, yet as enticing as this seems it is not always so wondrous. Indeed, many diver encounters with the strange are memorable for just how terrifying they are, and here we will look at some diver encounters with unexplained mystery monsters that left them shaken and horrified. 

A very early account comes from all the way back in 1880, at the home of the famous Loch Ness monster, Loch Ness, Scotland. At the time, a diver by the name of Duncan MacDonald was sent to investigate a shipwreck at the Caledonian Canal entrance at Fort Augustus. The dive was supposed to be routine and conditions were clear, but things would soon get chaotic and very mysterious. According to author Nicholas Witchell in his book The Loch Ness Story:

Not long after (descending), he sent urgent signals on his line to be immediately brought back to the surface. Shaking and ashen faced, he refused to say what he had seen for several days. When he had sufficiently composed himself, he told the tale of how he had seen a “very odd looking beastie ... like a huge frog” lying on the rock ledge where the wreck was lodged as he examined its hull.  He refused to ever dive in the loch again though it would appear this encounter was where Loch Ness ends and the canal begins.

Another report from Loch Ness was published in 1933 in the Dundee Courier and Advertiser, and was a report sent in by a reader concerning something that had happened to a man she had met in the village of Meffin. Her letter reads in part:

Once coming to “Meffin” I made the interesting discovery that one of the residents of this village also hailed from this part of Inverness-shire. After discussing persons and places the conversation turned round to the Loch Ness monster. “I remember,” he began, “how the villagers in that district used to talk about a monster being seen on Loch Ness, about three(?) miles from Invermoriston – that is, at Ruskich(?). The story runs that a gentleman sailing down the loch in his yacht was driven shorewards. The yacht sank and came to rest on a ledge of rock.

In order to secure some of his valuables the owner of the sunken yacht hired the Caledonian Canal diver – Honeyman by name – from the village of Clachnaharry. He intimated to the assembled onlookers that he would begin work the following morning. When the coast was clear, however, the diver, thinking that he and his crew would get something for themselves, donned his diving suit and descended into the water to make inspection.

When he got to the yacht it slipped off the ledge of the rock and disappeared into the depths. But then, to the diver’s intense horror, a huge beast, measuring about nine feet long and possessing a body as stout as that of an average man, passed in front of him. Whatever it may have been, the diver, who in very truth had ‘got the wind up,’ adamantly refused to descend into the water again.

Yet another underwater sighting of the Loch Ness monster was made by a man named Robert "Brock" Badger, who had an encounter with the Loch Ness Monster whilst diving in Urquhart Bay on Sunday 8th August 1971 in order to replace some mooring. He tells of his encounter:

We did the job of placing the mooring, and as the others loaded the tools and dinghy back into the van, I did a bit of snorkelling so the wetsuit did not get ripped on the gear. I swam out from the small floating jetty which was there in those days. A hundred yards or so from the jetty, the floor of the bay suddenly nose-dives into deep water. I had just passed this point and was about 10 or 15 feet below the surface, but was now in deep water and was thinking that I should turn and go back when I saw an object in front of me.

The water is of course full of peat and is like thick tea. As I got closer I could see a top and bottom to the object, but it extended left and right out of my vision. The surface of the object was rough textured and rounded in cross-section. I saw no protuberances in the part I could see. I'm not sure how far from the object I was, maybe 15-20 feet. It was moving from my right to my left, that is towards the main loch. This sounds like a long drawn-out sighting, but in reality it occupied only a couple of seconds. I realised what I was looking at, and decided that I should not be there. I have size 13 feet and my swim flippers are large and strong. I surfaced quickly and made for the pier as fast as I could.

Simon Dinsdale's eye was caught by me surfacing, and he said I was moving so fast that I was aquaplaning on my chest. As I made my way in, I was terrified that I was being chased, but I noticed Mr Menzies' nephews playing in a boat tied to the pier, and his black labrador coming into the water to meet me, so I risked a look back and realised that I was alone.

Strange, indeed. Moving on from Loch Ness, a very bizarre report comes from The Pine Barrens Institute, and details the alleged experience of a deep sea diver from Australia back in 1953. The unnamed witness was apparently diving in deep water and noticed a huge black mass looming in the murk, apparently just sort of hovering there in the current. This was startling enough as it was, but it would soon get more terrifying. As the diver stared in wonder at this immense mystery blob, a whitetip shark purportedly swam by it, after which it seemed to stop in mid-swim and get pulled into the mysterious mass to vanish, apparently sucked in by the beast. The diver would then say that he realized it was a gigantic jellyfish far larger than anything known, which had in front of his very eyes devoured a full-grown shark. The Pine Barrens Institute makes it clear just how big this jellyfish might have been in its report, saying:

Currently, the largest known jellyfish in the world is the Lion’s Mane Jellyfish (Cyanea capillata). The bell diameter (the “head”) of the Lion’s Mane can grow to over 6ft 7in wide, while the sticky tentacles can grow up to 100ft long. These jellyfish are found primarily within the cold waters of the Arctic, Northern Atlantic, and Northern Pacific oceans. The largest specimen of Lion’s Head washed up in Massachusetts Bay in 1870, and had a bell diameter of 7ft and tentacle length of 121ft.

Now, could a Lion’s Mane Jellyfish be the Jelly responsible for catching, killing, and “eating” the shark in Australia? While the L.M.J is capable of growing extremely long tentacles, the bell diameter is not large enough to encapsulate and digest a full grown whitetip shark. The generally agreed upon length of the shark is around 9.8ft long, although a record setting 13ft specimen has been caught before. This would make the shark bigger than the bell of the L.M.J. by almost 3ft. In order for a jellyfish to eat and digest its food, it needs to fully encapsulate the prey inside its “stomach”. The stomach of the jellyfish is known as the coelenteron, a single cavity inside the bell which serves as not only the stomach, but also as the mouth, intestines, and anus. When the food has fully made it inside the coelenteron, digestive enzymes and acids begin to break down the food and it is then absorbed into the body. But, if the food is larger than the small hole that leads inside the coelenteron, the jelly will release the food to drift away.

This means that the jellyfish that caught and ate the whitetip shark had to possess a bell which was 12ft or wider. In turn, this could mean that the tentacles of this mysterious gigantic jelly might have been a length of over 200ft or more.

The report also makes mention of a sighting of a massive jellyfish in 1969 off of Bermuda. In this report, divers Richard Winer and Pat Boatwright reported seeing a “giant purplish colored jellyfish with an almost pink outer bell rim pulsating through the water” with the diameter of its bell estimated as being nearly 100 feet across. They vacated the vicinity with great haste.

In 1988, a professional scuba diver named Robert Froster was diving near the coast of Florida when he noticed some strange disturbance in the water in his periphery vision. When he turned to see what it was, he saw a figure dashing through water that had been rendered murky and foggy through the stirring up of sediments. Whatever it was appeared to be undulating somewhat towards him, and when it got to within 20 yards the diver noticed that the thing had arm-like appendages that seemed to be tipped in talons and were reaching out towards him. As it drew closer still, Froster claimed that he could see that its top half had smooth skin, unmistakable breasts, and a head of flowing hair, while the bottom half was covered in scales. Whatever it was did not seem friendly, and the frightened diver would say of its gaze, “I’ve never seen such evil hate in the eyes of any human or animal before.” He was able to make it to the surface and aboard his vessel without further incident.

Also from the 1980s is the supposed experience of an unnamed diver who was out diving in the cave systems of Dublin Lake, in Cheshire County, in the U.S. state of New Hampshire. The diver apparently emerged from his dive babbling incoherently about the “monsters” he had encountered in the caverns below the murky lake. This mirrors another supposed incident in which a diving bell was lowered into the same lake but was unable to reach its destination as it had run out of tether. A scuba diver was sent to help out and disappeared. According to the tale, he was found days later, running through the nearby woods naked and rambling on about the horrible monsters he had seen in the lake. What did he see? No one really knows. 

In another account from August of 1991, a diver was out in the water near Cape Aya, on the Crimean Peninsula, Ukraine, in the Black Sea. He was about 100 meters off of the coast in calm seas under a full moon when he suddenly felt something poking at his shoulder. Turning around to see what it was, there was only the splashing of water all around. Thinking that his friends were playing a practical joke on him, the witness began to swim toward shore thinking nothing of it. That was when he experienced a strong strike to his shoulder, and this time when he turned around he was met with the sight of the face of a woman there in the water, although her eyes were described as being much larger than normal, and even creepier still she seemed to exude a bioluminescence.

The scared witness immediately made his way towards shore with as much vigor as he could muster, and behind him, he could hear thrashing in the water, which he forced himself not to look back at, afraid of what he might see. As he drew near to the shore, perhaps thinking that he was away from the thing that he had encountered, he felt another powerful jab to his shoulder, and he saw once again the face of the mysterious swimming woman, her eyes black and expressing what he called “disappointment.” The swimmer rushed onto shore screaming, and looking back he could purportedly make out a silvery body splashing on the surface to disappear down into the black depths. Although the terrifying experience was over, he found himself obsessed with what he had seen, even seeing the strange woman in his dreams, and felt compelled to go back several times to the same location but never saw her again.

Just as frightening as any of these reports is an eyewitness account by Reddit user u/Far-Ad-8219, who had an encounter with something as if from a nightmare. The report reads:

I remember a couple years ago, a buddy of mine had rented a boat out for my birthday to go out [on] the sea with. It was going perfectly fine, the boat was super nice, good for fishing, had a great deck. When he told me he was going to rent one, I thought to order a new fin to scuba with. It was a mono fin since I had never gotten a chance to use one. [I’d] been practicing with it, so it was perfect to use it out in the sea. We started to go out off the coast of the cape, and the water was a bit chilly, but not ice cold. We were maybe 22 miles out from the coast while still [within] eyesight of the shore. My friend brought fishing baits and rods for us to use later on… I was ready to get off the deck of the boat with my wetsuit and mono fin, my tank resting on my arm before I was going to dunk in. After a couple minutes, I had this really weird chill down my spine. Not paranoia, but superstition. I brushed it off and put my tank on my back, followed by my goggles.

I felt that weird superstition feeling again, but it quickly switched to paranoia when I saw a pair of glistening eyes in the ocean. At first … I thought was a shark… I’ve had my fair share of training for six years with sharks and other deep ocean water creatures, so I thought i’d be able to handle this. It slowly started making [its] way towards me when I got a better glimpse at it. It was HUGE, and I mean massive - its teeth were poking [out] the side of its jaw and [it] even had razor-sharp fins. And… I know this wasn’t a shark because they have a more smooth, rubbery type of flesh; this one had scales like a snake. Blood was pouring out of its mouth - it looked like it was ready for its next meal.

I attempted to hurry, but I was in shock... I finally cut out of shock the moment it started to swim more swiftly, but the mono fin could only go so fast in the water. My buddy was getting a little suspicious that I hadn’t come up with anything from the depths of the ocean. He looked over the boat deck and I guess could see me attempting to swim for my life as a dark shadow was inching closer. I eventually reached the boat and, out of breath, I told him to book it. We ended up not using the boat for the rest of the day and went home. To this day, I have no idea what it was, but in all my years of experience, I don't want to find out.

Also rather scary is a report from Lake Superior, in the United States, where diver Todd Ely was diving at the mouth of the Duluth Ship Canal on August 22, 2005. It was already a dangerous proposition, as the area is known for its fierce currents that can easily carry a diver away. For this reason, they had hammered a four-foot rebar spike into the sand, attaching the ends of their spools of guideline so they wouldn’t get sucked away or lost. The witness says of what transpired next:

Outside the great wall of the canal, we swam over the sand through perfect visibility forty feet deep, lacy light bands on our bodies from the day above. But at the canal’s mouth, a wall of brown silt pushed miles out into the open water, an underwater river within the lake. Whorls and eddies sprouted along its length into the distance. To swim across the breadth of it, we’d have to enter zero-visibility like a zone of night. We readied our nerve and kicked into the gloom.

In addition to the clicking sound of our guide line reels unwinding, I heard a thrumming sound, a guttural vibration I associated with an outboard motor sputtering on its way to starting up. We had timed our stunt to miss any cargo ship traffic. This sound was more like a pick of bone strumming thick tendons. It was biological and contained menace. Something heavy and fast bumped against me, at first I thought maybe it was a dead tree pushed by the current. Whatever it was grabbed my buddy and ran with him. I heard his guide reel spinning fast before it silenced. Our stake was dislodged, jerked from the lake bottom like a rod from the hands of an angler. My skin had been pierced, stabbed leaving a searing puncture wound. We had cast ourselves into the stream like bait. Fuck I miss you man, I feel terrible.

To make it all eerier, the witness would later die from “erythema, hypertension, and tachycardia” with symptoms that included swelling and vomiting, all caused by some sort of unidentified nerve venom. What is going on here? In some cases, the monster is not even clearly observed, although this doesn’t make the encounter any less bizarre or terrifying. One such account comes from Reddit user “AAAWorkAccount,” who says:

I'm in the Atlantic. Depth is about 30-50 feet with a lot of pocket reefs around. I swim away from a reef to see what is in that direction. Visibility is about 40 feet. In front of me, at the surface, right at the edge of visibility, I see a massive body. What I can see is around 2-3 feet thick, and about 6-10 feet long. I can only see a body, I can't see a tail or head. It is a light silver with somewhat darker golden or brown stripes. It was only there for a second, it must have been turning to go the other direction and I only saw a part of its body. I had never seen anything like that. I was curious and intrigued. I started to swim towards it to see what it was.

I got about 12 feet in that direction when a fright came through my body. It was a primal, undeniable feeling of absolute dread and horror. My body was telling me that whatever that thing was, I needed to get the hell out of the water as fast as I could. I stopped swimming towards it and immediately pivoted back to the boat. I swam on my back so I could keep looking behind me, in the direction that that thing had been. I don't know what that thing was. But it was massive. It was a giant and I was a fly. Some part of my animal brain knew what it was. And it knew that it was a danger.

Another account was given by Redditor “PizzND,” who at the time of his experience was overseeing a demolition dive. His spooky account reads:

It's necessary to explain that one way you can keep track of a diver is to watch their bubble stream. When a diver inhales, the helmet's demand regulator provides air from their umbilical. Then when they exhale, it is exhausted into the water and floats up to the surface. On topside you can watch the bubbles to get a general sense of where the divers are. Now on this occasion we were hundreds of miles from land, and had placed two divers in the water. About an hour into the dive, we started noticing something strange was happening. There were three distinct bubble streams coming from where they were working. At first we assumed that there was a current and it was affecting them. But soon we noticed a fourth set of bubbles coming from a distance. It stopped about 20 feet from the divers, near the other mysterious bubbles. We asked the divers, but neither could see anything out of the ordinary. Then, even from the surface, we heard a blood curdling screech from the waters. Then silence. The divers weren't too concerned, we hear strange things all the time. Sound travels well in the water, and you learn to assume it's a long distance away. But soon, it looked like the water in the distance was boiling, and it was getting closer. It wasn't boiling though. It was countless new bubble streams moving nearer to the location our divers were working. The supervisor ordered the divers to get onto the dive stage to be lifted back to surface. The bubbles were frighteningly close now, and the divers being lifted out said they had begun seeing shadowed figures in the distance. They couldn't quite make out what they were though. We elected to pull the divers out without completing their decompression stops and throw them into our hyperbaric chamber.

What in the world happened out there? Rather ominous is the case of a witness named Peter Wesker, a self-proclaimed marine biologist and diver, who had a bizarre experience in the cold dark depths off of Singapore. At the time he was employed at a drilling rig that operated at a depth of 400 feet and could drill down up to 30,000 feet, routinely working in inky blackness that was just barely kept at bay by diving lights. On one mission, things would get very odd indeed, and he says of what happened:

We were underwater at a pretty ridiculous depth. To put it into perspective, Everest reaches 29,035 feet. This drill, just beneath the surface, would go on for another 30,000ft on top of the 400ft between the sand and the water surface. We were right down at the ocean floor. You never really get used to the sensation at being at such incredible depths; having an endless abyss of darkness all around you, knowing you can’t swim to the surface because if you do, you’ll probably die on the way. There’s such a heavy feeling of reliance on the surface team to get you out of there that you begin to feel a little helpless. The noise didn’t help. We were searching around the metal supports of the oil rig’s structure, basically four massive pylons thrust into the ocean floor to hold the surface platform up. It was ridiculously daunting and large under the water, with rust caked all over the surface of the metal and more algae than I thought I’d ever have to see. A couple small schools of fish circled us as we scoured the place from… well, bottom to bottom.

That was when the noise began. It was subtle, at first, and it wasn’t just one sound. It was like a mix between a roller door opening and a mesh sliding door opening and closing loudly, but at the same time so distant and quiet. But it didn’t go away. “T32, Mike do you hear that?” I remember asking to my co-diver, Mike Davis. I was using my flashlight to search the sand for any source, but the visibility was so poor I could barely see 50ft ahead. It still sounded incredibly distant, like it was far, far beneath the surface. I proceeded to oblige and radio in to our surface team that there was an unconfirmed noise originating from beneath the surface. After a little while, they gave the order to continue the search. Reluctantly, we did. Until the noise grew again. And again. And again.

It had slowly turned from two, separate little sounds to a single, loud noise. Like an air raid siren screeching at us from below the depths. It continued to rise closer and closer, and we could feel the ocean floor shaking.

I cursed and made the call to ready the decompression chamber; we were leaving then and there, whether they agreed to it or not. The noise continued to roar towards us and the sand was shifting with its vibrations. My first thought was that the drill beneath the surface had broken and was coming up towards us, but it didn’t take me long to disregard that as utter nonsense. Every option, every potential ripped through my mind as we swam upwards as far as we safely could, while waiting for the diving bell to be delayed. The noise grew closer and closer until I was certain it was about to burst straight out of the sand. “Okay, that’s as high as we can go, stop here!” I shouted to my two co-divers, knowing this was the limit before hypoxia could set in. I calculated that on instinct, but checked my depth meter to confirm.

The noise was just below the surface, its rising and falling bloodcurdling screech making my stomach drop. I checked my sub-to-surface radio for replies, but static was the only noise coming through. They should have deployed the bell and confirmed by that point. Our inter-team comms were still operational though. I cursed again, but the noise drowned out any sound I had. It was so close I could practically reach out and touch the sound, its vibrations tearing through the water and sending ripples upwards, outwards and in all directions.

I saw the silhouette of a diver resuming his stroke upwards, before I shut my eyes as my head throbbed from the sound. It was only that point that I realized I couldn’t even here Davis talking anymore. Eventually, I must have blacked out. When I awoke, I was topside, being assessed by the auxiliary diver after decompression. In my hazy confusion, I never found out if Keller or Davis survived. Nothing significant happened from there, except a stern talking to from our dive commander. I was never to speak of this again to anyone, or consequences would be dire. That was it. That was my anti-climactic conclusion. Whatever happened while we were out cold, whatever they found down there had to be in the rest of that report. No matter the cost, I need to find out.

What was this? Was it some sort of seismic phenomenon, a mysterious sea monster, Cthulhu? Who knows? Here we have looked at a selection of reports that really lie out there in the realm of the strange. What did these people experience in the depths of our world's oceans and lakes? How can we explain such brushes with the odd? In the end, it shows that there are perhaps plenty of more things to be discovered under the waves, perhaps even things that should not be discovered.