More than 70% of our planet is covered by oceans, yet as of 2020, we've only explored a mere 5% of it. Who knows what might be hidden just beneath the surface: undiscovered species from the ocean’s depths, the resurrected Megalodon from the prehistoric past, or even a long-lost shipwreck. Could the fabled city of Atlantis be buried somewhere deep, or is there something far darker and more chilling lurking beneath? While researchers continue their search for the unknown, here are some ocean mysteries to reflect upon.
8. The 19th Century Shipwreck Discovery

On May 16, 2019, a team of scientists aboard the National Oceanic and Atmospheric Administration’s (NOAA) Okeanos Explorer in the Gulf of Mexico made a fascinating discovery. While testing a remotely operated vehicle, they came across what appeared to be the remnants of a shipwreck dating back over 200 years.
Upon closer examination, it was revealed that the ship was constructed with wood and had copper sheathing, measuring about 124 feet in length before it sank. However, this discovery only raised more questions than answers. Archaeologists still don't know the origin of the ship, its exact age, what happened to the crew, or even what kind of vessel it was.
The only clue discovered at the site was the number 2109 engraved on the rudder, along with iron and copper items scattered nearby. Burnt fragments of wood suggested the ship might have caught fire before sinking. After the discovery became public, Frank Cantelas from NOAA expressed hope that future expeditions would be launched to solve the mysteries surrounding the wreck.
7. Secrets of the Black Sea

Once known as both the Inhospitable Sea and the Hospitable Sea, the Black Sea is a vast repository of mystery. Like the Bermuda Triangle, it has been the site of strange creature sightings, unexplained phenomena, and strange disappearances. In 2000, Robert Ballard announced the discovery of evidence suggesting that people perished in a massive flood of the Black Sea. This discovery was linked to the biblical flood story in the book of Genesis, sparking much debate.
In the Middle Ages, both Turks and Russians reported seeing whirlpools in the Black Sea that swallowed ships and even entire islands. These whirlpools were said to suddenly appear in calm waters without warning. This led fishermen to avoid the area, believing it to be cursed.
In December 1945, five Soviet bombers vanished over the Black Sea, never to be found. Then, in 1990, a Greek plane also disappeared under mysterious circumstances. This led to the theory that a magnetic anomaly might be present, causing electrical malfunctions. In 1991, a Russian oil platform supposedly broke free from its moorings and drifted into the Black Sea. Investigations revealed that all 80 workers aboard the platform were missing, with their abandoned belongings and unfinished meals the only signs they had ever been there.
6. The Vanishing of the Namse Bangdzod

On 27 December 2018, the Namse Bangdzod, a 1,950-ton oil tanker with 11 crew members and a captain onboard, departed from Sampit, Central Kalimantan, heading for Tanjung Priok Port in Jakarta. It was scheduled to arrive the following day. However, on 28 December, all contact with the vessel was lost in Ujung Karawang waters. The last data input recorded by officials was on 3 January 2019.
The National Search and Rescue Agency, Basarnas, suspected that the tanker may have been hijacked by pirates. However, the Navy disagreed, pointing out that the route taken by the tanker was considered safe, and there was no ransom demand. The Navy also noted that the ship had been recorded shifting positions multiple times, moving from Jakarta Bay to Sunda Kelapa Port, but it was not found at either location.
Maritime expert Oloan Saut Gurning stated that an accident seemed unlikely, as no distress signal had been sent, and he didn’t believe the tanker could have been drifting at sea without being located by the Navy. Basarnas continued its search for four days before the police and Navy took over the operation. To this day, the tanker remains missing.
5. The Infamous Death Island

Koh Tao, a stunning island located on the western side of the Gulf of Thailand, is known for its name, which translates to “Turtle Island,” and its vibrant coral reefs, home to beautiful sea creatures, including turtles. The island offers a variety of accommodations, from budget-friendly options to luxury resorts, making it a perfect destination for holidaymakers… or so it appears on the surface.
Beneath its beauty and luxury lies a disturbing undercurrent of criminal activity. Dark rumors of body parts floating in shallow waters and the island being controlled by a local mafia came to light following a string of mysterious deaths. As a result, Koh Tao, also known as 'Death Island,' has gained a reputation that deters many from visiting. In 2012, Ben Harrington tragically died after his motorcycle collided with an electricity pylon. He was alone at the time of the accident, and his wallet and watch were never found. His mother suspected foul play, particularly after the coroner hesitated to label the cause of death as “accidental.”
In September 2014, two backpackers, Hannah Witheridge and David Miller, were discovered murdered on the same beach where Ben Harrington had stayed. It was later revealed that Hannah had been raped before her death. Local police mishandled the investigation, failing to secure the crime scene or monitor the island’s port. Instead, they focused on interrogating two Myanmar migrants, who were later convicted and sentenced to death for the murders. However, authorities allegedly neglected to collect DNA samples or test the victims' clothing. Two weeks after the murders, another body was found on the same beach: 24-year-old Luke Miller was discovered at the bottom of a swimming pool.
At the age of 23, Valentina Novozhyonova mysteriously disappeared from a Koh Tao hostel, never to be found again. Six weeks later, a body was discovered, but it wasn’t hers. Instead, it was the remains of Belgian tourist Elise Dallemagne, her body burned and wrapped in T-shirts. In January 2015, another 23-year-old, Christina Marian Annesley, was found dead in a Koh Tao bungalow. Her body was left in a temple for several days before an autopsy was conducted, causing a UK coroner to reject the Thai results due to mishandling.
The string of unsolved deaths fueled rumors about a possible serial killer family on the island or the involvement of the local mafia. Regardless, no resolution has been found, leaving the grieving families without answers and justice.
4. A Shipwreck and Its Curse

The HMS Wasp, constructed in 1880, was originally designed for fisheries inspections and lighthouse duties, but it also carried bailiffs to oversee evictions in various locations. The ship was well-known in Derry, often docked alongside its sister ship, the HMS Valiant. On 21 September 1884, the Wasp set sail for Moville to pick up bailiffs and other staff who were heading to Innistrahull Island for an eviction. It was a familiar route, and the crew's morale was high.
Tragedy struck shortly after. At 3:45 am, the Wasp struck the rocks off Tory Island. The ship sank within 30 minutes, taking the lives of 50 crew members, with only 6 surviving the disaster.
A survivor later recounted that as the Wasp approached Tory Island, it was sailing under only wind power with its boilers shut off. Instead of navigating around the island, the ship was directed to pass between the Tory light and the mainland, a path that was considered riskier. The survivor also claimed that all senior officers were asleep at the time, leaving junior crew members in charge of the vessel.
Despite this, many found the circumstances surrounding the incident to be highly unusual. The ship struck the rocks directly beneath the lighthouse, the sea was calm, and the weather was clear. While the Tory light remained visible after the sinking, there is debate over whether it was on when the Wasp was approaching the island. Some speculate that the light was deliberately extinguished to prevent the Wasp from delivering bailiffs to the island. Others suggest that the ship had been cursed by the Tory’s Cursing Stone, ultimately leading to the catastrophe. An Admiralty inquiry offered no explanations, leaving the sinking of the HMS Wasp enveloped in mystery.
3. Sea Monsters

Sea monsters have long been subjects of legend, with tales of terrifying creatures lurking beneath the waves. From the Kraken to colossal squids and vicious sharks, these stories stir the imagination. One particularly well-known account comes from 1889 when G. H. Hight and a companion traveled to Madagascar. There, villagers told them of a massive green sea serpent that had attacked a fishing boat, devouring one of its crew members. The beast chased the remaining survivors to the beach before disappearing into the sea. Hight later organized a search party and saw the serpent himself, but despite shooting at it, they were unable to kill it. No evidence has ever surfaced to verify this story, which was first published in The Washington Herald in March 1909.
Another disturbing tale surfaced in Fate Magazine in 1965. In 1962, 16-year-old Edward Brian McCleary set out for a day at sea in the Gulf of Mexico with four friends: Warren Felly, Eric Ruyle, Larry Bill, and Brad Rice. McCleary was the only one to return, visibly shaken and terrified. He told police that a sea monster or dragon had appeared, attacking and killing his friends. He described the creature as having a 12-foot-long neck, green scales, and a turtle-like head.
McCleary denied accusations that he had mistaken a submarine for the monstrous sea creature he described, claiming that news outlets had only agreed to publish his story on the condition that he omitted details of the sea monster. Larry Bill’s body was allegedly recovered, having drowned, but the other three boys were never found. Unsurprisingly, very few believed McCleary’s account of a sea creature emerging from the depths to attack the group of teens. The events of that day remain an unsolved mystery.
2. Utsuro-Bune

A strange and mysterious story, now woven into the fabric of folklore, tells of a peculiar vessel that washed up on the shores of Japan on 22 February 1803. Fishermen who encountered the boat described it as round in shape, with windows at the top and metal strips along the bottom. Upon boarding the boat, they discovered a lone occupant sitting against a wall covered in strange markings. The woman, who had red hair, was clutching a box in her lap and could not communicate with the fishermen, nor would she part with the box.
The event became known as the utsuro-bune, or 'hollow ship.' At the time, the fishermen speculated that the woman could be a princess who had been carrying the head of her deceased lover in the box. Uncertain of what to do with her, they decided to release the boat back into the sea, leaving the woman inside. They were perplexed by the unfamiliar materials—the glass windows and metal strips—and eventually concluded that the woman might have been an alien.
Some rejected the alien theory, instead suggesting that the red-haired woman might have been a Russian spy. In modern times, experts propose that the boat could have had a dome structure for better seaworthiness, explaining its rounded shape. However, no further theories have been put forward to explain the woman’s identity, the contents of the box she clutched, or the mysterious writings on the walls of the vessel.
1. Mysterious Divers

Divers are not immune to strange occurrences when exploring the ocean’s depths. Not only have some divers heard the sound of boat engines revving when the ocean surface above them is clear of boats, but there have also been reports of eerie grinding noises emanating from the engine room of the Japan Hoki Maru ship, which sank in Truk Lagoon in 1944.
In 2007, a group of divers were exploring the waters around Grenada. After a tiring dive, the group returned to their ship to review their notes from the exploration. One diver asked if anyone else had seen another diver in a white shirt waving at their group. No one had seen this mysterious figure, and a head count confirmed that everyone was present. There were no other boats or ships in the area. To this day, the identity of the diver in the white shirt remains unknown.
In 2012, scuba instructors in Santa Rosa, California, had an unsettling experience while diving. They spotted a mysterious diver with a pink tank floating near a blue hole. When they swam closer to investigate, the diver vanished just before they reached the hole. Disturbed, the instructors immediately contacted the police, who informed them that others had reported seeing the same figure near the blue hole before it disappeared.
