If the recent Maldives diving tragedy has taught us anything, it's that the ocean can be a dangerous and unpredictable place. Five highly trained divers lost their lives in May, after an underwater expedition went horribly wrong. Their bodies were eventually recovered from a cave, days after they failed to resurface. But not before a sixth person - a navy diver tasked with finding them - suffered the same fate.
The world watched in horror as the drama unfolded... It was a stark reminder that even the most skilled divers aren't immune to unexpected disasters. People have been sharing their own diving nightmares in a series of online threads. Bored Panda has put together a list of the scariest ones. From underwater explosions, earthquakes, running out of oxygen, and encountering giant sea creatures, many of these tales might leave you with Thalassophobia - a fear of deep water.
#1
This is the scariest thing but was also so much fun.
I was going through a wreck and I turned a corner into a fairly open room and there was the biggest Goliath grouper I've ever seen just sitting in this room a few feet from me. Scared the soul out of me for a few seconds because I had never seen one on this island. He made a hilarious omg face as well and swam out the door.
I was going through a wreck and I turned a corner into a fairly open room and there was the biggest Goliath grouper I've ever seen just sitting in this room a few feet from me. Scared the soul out of me for a few seconds because I had never seen one on this island. He made a hilarious omg face as well and swam out the door.
Report
29points
Some of these horror stories might have you terrified to even dip your toe into the ocean, let alone venture into its depths. But diving is generally considered safe, provided you have the correct training, equipment, and only dive within your limits.
According to the Divers Alert Network (DAN), cardiovascular events — including heart attacks and fatal arrhythmias — remain the single largest identifiable cause of diving fatalities. DAN's 2025 Dive Incident Report reveals that this was the cause of about a quarter of all fatal dive incidents that year, where a contributing factor could be established.
Most of the victims were middle-aged to older male divers, and they often ran into trouble during or immediately after ascent. Many of them had pre-existing but previously undiagnosed cardiac conditions. It's one of the reasons that DAN recommend pre-dive medical screening, especially if you're a new diver, over 40 years old, and/or anyone returning to diving after a health-related break.
#2
I am a blackwater diver. At night, we motor about five miles offshore and drift for roughly two hours to observe the animals that migrate toward the surface after dark. In my region, this usually happens over water that is 600 to 900 feet deep. We see all kinds of unusual things, and anyone who dives blackwater regularly has at least one moment when their body reacts before their brain does. It is that sudden drop in the stomach, the adrenaline surge, and the instinctive realization that something demands your full attention. Here are two of mine.
1. Broadbill swordfish
Broadbill swordfish (Xiphias gladius) sit at the very top of the food chain for these vertical migrators. Many of them live their entire lives without ever seeing the sun, and their eyes are extraordinarily sensitive, like extreme versions of a cat’s eyes. When one moves through a group of divers, our 10,000 to 30,000 lumen lights become the brightest things it has ever encountered. The light reflects straight back out of their eyes as a vivid green beam a few inches thick. You can watch that beam flick from diver to diver, like the eye of sauron, scanning the group in a way that immediately triggers your monkey brain to "DO SOMETHING".
These are also one of the very few fish known to charge or attack divers. Being approached by even a “small” seven-foot swordfish is deeply unsettling. We have had a diver impaled by one, and it took five months of rehabilitation before he was able to return to the water. Knowing that history changes how your body reacts when those green beams appear in the dark.
2. The black cone
On another dive, I was around 85 feet photographing a diamond squid when I noticed something below me at roughly 130 feet. It looked like a massive, perfectly smooth black cone. At first I thought it might be some kind of egg mass, but it was far too uniform. Then it registered just how large it was. I could only see the first 15 feet or so, and it continued downward into complete darkness.
The sense of dread that washed through me, starting at the back of my neck and moving through my body, is something I will never forget. I felt completely frozen, my mind was racing with "WHAT the F**K is THAT". Thankfully, my training kicked in, and almost subconsciously, I made a controlled ascent back to around 40 feet to regroup with the rest of the divers until I calmed down. When I asked if anyone else had seen it, the response was a casual, “Yeah, that thing was huge.”
The best explanation we could come up with was that it might have been a large sheet of industrial black plastic drifting vertically in the water column. Or maybe that is just the version of the story I tell myself.
Theres other cool less terror-inducing stories like realizing the floor was moving, but how could that be, we're over 640ft.... until we realized it was a horizon to horizon school of football size bonita, a river of fish uniformly at the same depth, slightly undulating.
1. Broadbill swordfish
Broadbill swordfish (Xiphias gladius) sit at the very top of the food chain for these vertical migrators. Many of them live their entire lives without ever seeing the sun, and their eyes are extraordinarily sensitive, like extreme versions of a cat’s eyes. When one moves through a group of divers, our 10,000 to 30,000 lumen lights become the brightest things it has ever encountered. The light reflects straight back out of their eyes as a vivid green beam a few inches thick. You can watch that beam flick from diver to diver, like the eye of sauron, scanning the group in a way that immediately triggers your monkey brain to "DO SOMETHING".
These are also one of the very few fish known to charge or attack divers. Being approached by even a “small” seven-foot swordfish is deeply unsettling. We have had a diver impaled by one, and it took five months of rehabilitation before he was able to return to the water. Knowing that history changes how your body reacts when those green beams appear in the dark.
2. The black cone
On another dive, I was around 85 feet photographing a diamond squid when I noticed something below me at roughly 130 feet. It looked like a massive, perfectly smooth black cone. At first I thought it might be some kind of egg mass, but it was far too uniform. Then it registered just how large it was. I could only see the first 15 feet or so, and it continued downward into complete darkness.
The sense of dread that washed through me, starting at the back of my neck and moving through my body, is something I will never forget. I felt completely frozen, my mind was racing with "WHAT the F**K is THAT". Thankfully, my training kicked in, and almost subconsciously, I made a controlled ascent back to around 40 feet to regroup with the rest of the divers until I calmed down. When I asked if anyone else had seen it, the response was a casual, “Yeah, that thing was huge.”
The best explanation we could come up with was that it might have been a large sheet of industrial black plastic drifting vertically in the water column. Or maybe that is just the version of the story I tell myself.
Theres other cool less terror-inducing stories like realizing the floor was moving, but how could that be, we're over 640ft.... until we realized it was a horizon to horizon school of football size bonita, a river of fish uniformly at the same depth, slightly undulating.
24points
#3
About ten years ago, I was diving using rented equipment because my own pressure gauge was faulty due to salt buildup. Unfortunately, the rented gauge was also inaccurate—the zero mark was offset to 10. When it showed 15, I believed I still had sufficient air and began my ascent for safety stop.
During the safety stop, the gauge dropped to 10 and suddenly delivered no air. I tried breathing again but got nothing. I looked toward my buddy, who was about 2–3 meters below me and facing another direction. When I looked up, I could see sunlight above, so I made an emergency ascent, exhaling continuously and pushing all the remaining air out. I reached the surface safely.
That incident ended my diving hobby forever. Now, after nearly ten years, I’m planning to return to diving—this time with reliable personal gear, better fitness, refreshed training, and most importantly, a small secondary cylinder as a backup for added safety.
During the safety stop, the gauge dropped to 10 and suddenly delivered no air. I tried breathing again but got nothing. I looked toward my buddy, who was about 2–3 meters below me and facing another direction. When I looked up, I could see sunlight above, so I made an emergency ascent, exhaling continuously and pushing all the remaining air out. I reached the surface safely.
That incident ended my diving hobby forever. Now, after nearly ten years, I’m planning to return to diving—this time with reliable personal gear, better fitness, refreshed training, and most importantly, a small secondary cylinder as a backup for added safety.
22points
According to DAN's report, running out of air and buoyancy-related incidents accounted for the next largest share of non-fatal serious incidents. This often comes down to divers not planning their expeditions properly and/or not completing their pre-dive equipment checks.
The report also found that physical exertion often triggering both cardiovascular and near-drowning incidents.
"Divers who encounter unexpected current, rush gear preparation, or exhaust themselves swimming to a distant surface point are significantly over-represented in incident reports relative to their proportion of total dives," notes the Dive Journal.
It's therefore important for recreational divers to stay fit, and keep up their cardio training.
#4
When using cutting tools underwater, a lot of hydrogen gas is produced. If you don’t adequately ventilate the area behind what you are cutting, hydrogen gas can build up and be ignited by the cutting torch. The result is an explosion funneled through the hole being cut, and in the case I witnessed, blasting clear through the divers face plate.
20points
#5
My instructor almost ended himself and me with him in the process.
Was broke, so I went dive centre shopping to find the cheapest one. First mistake.
I find a place and they decide to take me. It’s just me and the instructor diving. We get in the water and start swimming toward the Blue Hole. It’s not far, and I’d done it before.
Did I mention the instructor is new?
We get close to the entrance of the hole, but it’s at around 7 metres and we’re too deep so we miss it. We keep swimming. I know we missed it, but I follow my instructor. We’re just swimming nonstop at this point, him in front, me behind, trying to make the most of this failed Blue Hole dive.
Oxygen is running out.
He asks how much I have left and I give him the hand signal each time. When I signal 70 bars, he reacts like he’s surprised, panics, swims faster, then at 40 bars he hands me his octopus. We do a safety stop and ascend.
I look out of the water and we’re by the “Abu Gallum Protected Site” sign. That’s at least 300 metres away from the Blue Hole.
Now we need to get to shore. We are forced to walk on the rock and coral because there’s nowhere else to go, and he doesn’t want anyone else witnessing his mess up. Which he managed to do being a quarter km from the dive site.
We still have all our gear on. Waves are crashing against the rocks and us. I keep my centre of gravity low, always trying to find grip. Him? Not so much. Walking normally, wobbling here and there, trying to rush.
Then I see the wave.
It’s huge.
It hits him and he disappears into the foam. Gets tossed around for a bit, then somehow manages to get out of it.
When we finally make it back to shore, I look at him, and he looks like he just walked out of a crime scene where he was the victim
That was the last time I cheaped out on diving.
Was broke, so I went dive centre shopping to find the cheapest one. First mistake.
I find a place and they decide to take me. It’s just me and the instructor diving. We get in the water and start swimming toward the Blue Hole. It’s not far, and I’d done it before.
Did I mention the instructor is new?
We get close to the entrance of the hole, but it’s at around 7 metres and we’re too deep so we miss it. We keep swimming. I know we missed it, but I follow my instructor. We’re just swimming nonstop at this point, him in front, me behind, trying to make the most of this failed Blue Hole dive.
Oxygen is running out.
He asks how much I have left and I give him the hand signal each time. When I signal 70 bars, he reacts like he’s surprised, panics, swims faster, then at 40 bars he hands me his octopus. We do a safety stop and ascend.
I look out of the water and we’re by the “Abu Gallum Protected Site” sign. That’s at least 300 metres away from the Blue Hole.
Now we need to get to shore. We are forced to walk on the rock and coral because there’s nowhere else to go, and he doesn’t want anyone else witnessing his mess up. Which he managed to do being a quarter km from the dive site.
We still have all our gear on. Waves are crashing against the rocks and us. I keep my centre of gravity low, always trying to find grip. Him? Not so much. Walking normally, wobbling here and there, trying to rush.
Then I see the wave.
It’s huge.
It hits him and he disappears into the foam. Gets tossed around for a bit, then somehow manages to get out of it.
When we finally make it back to shore, I look at him, and he looks like he just walked out of a crime scene where he was the victim
That was the last time I cheaped out on diving.
Report
20points
#6
Not really terrifying but i'll share my weird stories
* in Galapagos a sea lion played with me and then brought me a red lipped bat fish as a gift. I was chilling at about 20 feet for a little decompression and it started swimming around me playing with my bubbles as normal. Then the sea lion dove down the wall and came back a few minutes later with a the batfish in its mouth. The Sea lion swam around me twice in a circle then dropped the fish directly in front of me and swam away. I have all of this in photos. No one on the boat believed me until I showed them.
* I saw a sea turtle full blown body slam my dad, that was funny. We think it was defensive over a female nearby.
* in Galapagos a sea lion played with me and then brought me a red lipped bat fish as a gift. I was chilling at about 20 feet for a little decompression and it started swimming around me playing with my bubbles as normal. Then the sea lion dove down the wall and came back a few minutes later with a the batfish in its mouth. The Sea lion swam around me twice in a circle then dropped the fish directly in front of me and swam away. I have all of this in photos. No one on the boat believed me until I showed them.
* I saw a sea turtle full blown body slam my dad, that was funny. We think it was defensive over a female nearby.
Report
19points
Technical diving is considered the more extreme form of diving. It involves scuba diving that exceeds recreational limits, like depths beyond 130 feet, mandatory decompression stops, and navigating overhead environments like caves or shipwrecks. It also requires specialized gas mixtures, advanced equipment, and rigorous training because direct ascent to the surface is impossible.
#7
Maybe not "terrifying," but a Titan triggerfish protecting its nest during their nesting season is *not* something you ever want to be near.
Report
18points
#8
On a dive in Fort Lauderdale, DM had a leaky o-ring and was completely out of air by the time we hit 65 feet. Somehow no one, not even him, noticed the steady bubbles streaming up from behind him as he descended. He turned to me when we hit bottom, and I could tell he was distressed, and he gave me the "no air" hand signal. I immediately swam over and gave him my secondary reg, then escorted him back slowly to the surface. It was my first blue water dive, and I was the only other diver who happened to be within 15 ft of him. Could have been a lot worse.
18points
According to DAN's report, technical diving — including deep recreational, rebreather, and overhead environment diving — is becoming increasingly popular but still has a proportionally lower per-dive fatality rate than recreational open-water diving. Experts believe this is because of the more rigorous training standards and pre-dive planning.
#10
I was guiding a dive in Australia and a kid in my group was digging around in the sand and he pulls up a cone snail.
If you aren't familiar with cone snails they are also known as "cigarette snails" because if they sting you, you have just enough time to smoke a cigarette before it ends you
I immediately slapped out of his hand and was mentally preparing to haul a passing kid to the surface.
Luckily it was just the empty shell, but for a brief moment, my heart rate went through the roof.
If you aren't familiar with cone snails they are also known as "cigarette snails" because if they sting you, you have just enough time to smoke a cigarette before it ends you
I immediately slapped out of his hand and was mentally preparing to haul a passing kid to the surface.
Luckily it was just the empty shell, but for a brief moment, my heart rate went through the roof.
Report
17points
#11
Once in a dive we all went down looking for the ground expecting it to be there at around 40 to 50 ft. We went past 40 or 50 we went all the way down to 120 and there was still no ground. Turns out we had drifted a bit and we were out in the deep blue. We didn't know this we were all just sitting at 120 ft looking around pointing at each other. I remember looking down and in every direction and just seeing absolutely nothing and it was the most strange experience. Because of my training I just tried to stay calm and tried not to think too hard about what we were looking at. But it was hard not to let your mind spiral into panic despite 100 ft vis, looking out at nothing was peaceful and terrifying in retrospect.
Report
17points
#12
I saw/heard a 5 point something earthquake underwater. I was diving with a group during the big earthquake swarm event in southwest Puerto Rico in early 2020. It was strange, like this rumbling all around, a big crack sound, and then the whole ground kind of jumped, the sand just lifted and dropped, like when a dog or something bumps up under a table. We all looked at each other all scared, but the fish seemed completely unbothered.
Report
17points
#13
Frankly it was not terrifying just weird.
In Aruba, and I hear a really weird sound and it is getting louder.
In in the end it was one of those "submarines" that allow tourist to go underwater. Its more like you sit in a hull with windows and the hull is underwater. The boat is not truly submerged.
Anyway our whole dive group went up to it and waved in the windows. My wife got to scare some tween who was too busy on her phone to participate. She gave the girl quite a jump scare when she knocked on the window.
In Aruba, and I hear a really weird sound and it is getting louder.
In in the end it was one of those "submarines" that allow tourist to go underwater. Its more like you sit in a hull with windows and the hull is underwater. The boat is not truly submerged.
Anyway our whole dive group went up to it and waved in the windows. My wife got to scare some tween who was too busy on her phone to participate. She gave the girl quite a jump scare when she knocked on the window.
Report
17points
#14
Was snorkeling off Catalina and saw an older scuba diver clinging to kelp for dear life, eyes bulging and panicked. He and his buddy had taken a sailboat to dive a point, completely obvious to the current that sometimes rips around it. I ditched my weight belt and dove down, pulling him to the surface. Once he surfaced he kept screaming he was going to pass away until I inflated his BC and calmed him down. His buddy had just accepted the current and came to the surface roughly 100 yards away. He kicked up later acting aloof. After I told him to get out and stop diving, they climbed onto their sailboat without any Thank-You’s.
If that was yall two and by chance you’re reading this, you’re welcome 😂.
If that was yall two and by chance you’re reading this, you’re welcome 😂.
Report
16points
#15
I saw a sheep crab eating an octopus alive in Monterey Bay. It wasn’t all that creepy compared to what others have seen but it was sad to see what is basically a cockroach eating something so intelligent.
Report
16points
#16
Once was diving a site called Bushrangers bay, which is adjacent to a quarry. Wasn’t aware of this at the time. The site is home to a nearly constant presence of Grey Nurse Sharks (aka sand tigers, raggies). Once on a dive there all of a sudden an enormous noise started up randomly. It was shaking every bone in my body and the seabed seemed to be shaking. I immediately thought there had been some sort of earthquake, or even a sonar probe from a military submarine scanning the area. My buddy and I were about to call the dive but we noticed the sharks weren’t freaking out like us, so we stayed. Turns out the noise was just created by quarry blasting. Goes to show how a completely normal action happening kilometres away from you can be turned into something scary due to how sound and vibrations travel underwater.
Report
16points
#18
On a 30m (90ft) wreck dive in the Red Sea.
One in the dive group didn’t do their due diligence on the boat. Nor did they on the buddy check. We all get in and descend. Get down to the full depth and start exploring the top side. Visibility is good and him and his buddy is at a good distance from each other.
Suddenly he tries to breath but it’s like trying to breath through a brick wall. Nothing. His buddy is busy with the wreck. Too far away. I see him but am too far away since he’s not my buddy. One of the guides get to him fast and he gets the octopus and can breathe again.
When we get back on the boat and do a debrief, it turns out he was sloppy turning his air on. Didn’t do it fully but maybe half way on. So when the air started to go a bit lower, the membrane just shut off the air flow, and despite having more than half a tank left with the air gauge showing that he got nothing.
It was scary for us all, and absolutely terrifying for him and his buddy. Could have been so much worse.
One in the dive group didn’t do their due diligence on the boat. Nor did they on the buddy check. We all get in and descend. Get down to the full depth and start exploring the top side. Visibility is good and him and his buddy is at a good distance from each other.
Suddenly he tries to breath but it’s like trying to breath through a brick wall. Nothing. His buddy is busy with the wreck. Too far away. I see him but am too far away since he’s not my buddy. One of the guides get to him fast and he gets the octopus and can breathe again.
When we get back on the boat and do a debrief, it turns out he was sloppy turning his air on. Didn’t do it fully but maybe half way on. So when the air started to go a bit lower, the membrane just shut off the air flow, and despite having more than half a tank left with the air gauge showing that he got nothing.
It was scary for us all, and absolutely terrifying for him and his buddy. Could have been so much worse.
15points
#19
My first ever dive was in the UK, doing my Open Water test in March. Everything goes wrong all at once. The drysuit starts leaking 5C water, and as I’m struggling to fix it I knock my mask off and the second stage regulator (the mouthpiece bit) starts free flowing. The free flow causes a drop in pressure in the first stage, which causes the first stage to ice up. Within a few seconds of free flow, the first stage is now a block of ice. I try to swim upwards but the leak has caused my drysuit to accumulate large amounts of freezing water and I can’t feel my legs while my lips have started turning blue.
I got it do most of the Open Water drills in a real life setting though so that was pretty cool. Luckily it was pretty shallow.
I got it do most of the Open Water drills in a real life setting though so that was pretty cool. Luckily it was pretty shallow.
Report
15points
#20
Diving in Bonaire “angel city” dive site with my partner. Were the only two out there swimming in the channel between to reefs. A GIANT moray eel swims out of the reef. Dude could have probably eaten a small child, was about 4 ft long with a head the size of a basketball. A legit sea serpent.
Report
15points