The Devil’s Sea: Japan’s Bermuda Triangle and the Ships That Never Came Back

About 100 kilometers south of Tokyo, where the Philippine Sea stretches toward the Pacific, there is a stretch of water that Japanese sailors have called Ma no Umi for centuries. It translates, roughly, as the Sea of the Devil. For generations, fishermen reported strange fogs, sudden storms, and boats that went out and never returned. Ancient Chinese mythology placed dragons beneath the surface — creatures hungry enough to pull ships straight down. The legend was old, specific, and very local, until an American author got hold of it in the 1970s, added some invented statistics, and turned it into Japan’s answer to the Bermuda Triangle.

The real story is more interesting than the myth. It’s also considerably stranger.

Where It Is and Why It’s Actually Dangerous

The Devil’s Sea — also called the Dragon’s Triangle — sits in the western Pacific, in a rough zone connecting Japan, Taiwan, and the island of Guam. It overlaps significantly with the Philippine Sea, one of the deepest ocean regions on Earth, and sits directly above the Pacific Ring of Fire.

That last part matters enormously. The Ring of Fire is a belt of intense seismic and volcanic activity running around the edge of the Pacific Plate, and the Devil’s Sea sits over one of its most geologically active sections. Underwater volcanoes erupt in the region regularly enough that new islands occasionally surface and then sink again within years. Existing islands shift. The seafloor moves in ways that surface navigation cannot reliably predict.

Beyond the geology, the area experiences some of the most severe weather in the entire Pacific. Typhoons form and intensify in the western Pacific at higher rates than almost anywhere on Earth. Strong, complex currents bring warm and cold water together in ways that produce sudden, dramatic changes in sea conditions. Fog forms fast. Swells arrive without much warning. For small fishing vessels with limited radio capability and no GPS, this combination made — and still makes — these waters genuinely treacherous.

None of that is mysterious. All of it is real.

The Legend and What Actually Happened

Japanese sailors have been wary of these waters for a long time. The legends date back at least to the Mongol invasions of 1274 and 1281, when Kublai Khan sent massive fleets toward Japan and typhoons destroyed both of them. The Japanese called these storms kamikaze — divine winds — and interpreted them as supernatural protection. Naturally, the waters that had swallowed two of history’s largest naval fleets became a place of deep dread.

For centuries after, fishing communities along Japan’s southern coast passed down warnings about the sea. Boats disappeared. Some losses pointed clearly to storms. Others had no explanation that satisfied anyone. The name Ma no Umi accumulated more weight with every ship that didn’t come home.

Then, in September 1952, the research vessel Kaiyo Maru No. 5 disappeared with all 31 people on board. Japan’s Hydrographic Office had sent the ship to study volcanic activity near the Myōjin-shō seamount — an active underwater volcano south of the Izu Islands that had been erupting intermittently since earlier that year. On September 24, a volcanic eruption destroyed the vessel. Crews later recovered debris from the site. The cause was clear: an underwater volcano, erupting at the worst possible moment.

That is a tragedy. It is not a mystery.

How Charles Berlitz Made It Famous

In 1974, American writer Charles Berlitz published The Bermuda Triangle, a book that became a global bestseller by collecting and dramatizing Atlantic disappearances into a single narrative of supernatural geography. The book sold millions of copies. It was also, as subsequent researchers demonstrated thoroughly, full of fabricated details, inflated casualty figures, and events that either didn’t happen the way Berlitz described or didn’t happen at all.

Berlitz saw an opportunity to apply the same formula to the Pacific. In his telling, the Devil’s Sea was a parallel phenomenon — Japan’s own zone of supernatural disappearance. He claimed that nine modern ships and several hundred crew members had vanished without explanation between 1950 and 1954. He described the Kaiyo Maru No. 5 as carrying over 100 people, sent to investigate these mysterious losses, and implied the ship had vanished without any explanation. He further stated that Japanese authorities subsequently declared the entire region a danger zone.

Almost none of that was accurate. The ship carried 31 people, not over 100. Its loss had a documented cause. The danger zone Japan’s government designated covered only a small area around the Myōjin-shō seamount specifically — a 10-mile radius around an active underwater volcano — not a vast triangular region of inexplicable paranormal activity. Moreover, most of the other vessels Berlitz cited were small fishing boats, not military ships, and their losses were consistent with the region’s weather patterns.

In 1989, Berlitz pushed further still, publishing The Dragon’s Triangle, adding more incidents and expanding the mythology considerably. By then, the legend had taken on a life of its own.

Larry Kusche and the Paper Trail That Didn’t Exist

In 1975, a reference librarian at Arizona State University named Larry Kusche published a direct response to Berlitz. His book, The Bermuda Triangle Mystery Solved, did exactly what the title promised. As a librarian, Kusche knew how to dig. He contacted the Coast Guard, the Air Force, Lloyd’s of London, military agencies, and newspaper archives. He tracked down primary sources for every incident Berlitz cited, and what he found — case by case — was that most of the Bermuda Triangle’s dramatic disappearances had straightforward explanations that Berlitz had either ignored or actively misrepresented. Events described as occurring in calm weather had actually taken place during storms. Ships described as vanishing without trace had left recoverable wreckage. Several incidents Berlitz placed inside the Triangle’s geography had occurred far outside it.

Kusche then applied the same scrutiny to the Devil’s Sea. He contacted Japanese government offices and maritime authorities to verify Berlitz’s claims. Strikingly, government offices related to the sea had no record of a danger zone called the Devil’s Sea. Japanese maritime officials were unfamiliar with the region by that name entirely. When Kusche searched Japanese newspapers and literature for references to the Dragon’s Triangle as a named location, he found nothing predating the early 1970s — nothing, in other words, predating the Western interest that Berlitz himself had generated.

Kusche concluded that the legend of the Devil’s Sea had been largely invented in America and then reflected back at Japan as ancient maritime tradition. The actual Japanese term Ma no Umi simply means dangerous sea, and sailors have applied it to numerous treacherous stretches of water throughout Japanese history. It is a description, not a proper name for a specific paranormal zone.

What’s Real

Stripped of Berlitz’s embellishments, the Devil’s Sea remains a genuinely hazardous region. Ships have been lost there, and the Kaiyo Maru No. 5 disaster was real and devastating. Typhoons in the western Pacific are severe. The seafloor is volcanically active in ways that create unpredictable surface hazards.

In 1980, for instance, the MV Derbyshire — a British bulk carrier twice the size of the Titanic — sank roughly 230 miles off Okinawa during Typhoon Orchid. All 44 people on board died. Investigators eventually located the wreck and determined the cause: structural failure under extreme storm conditions, combined with design flaws in the vessel. No mystery. Just a massive storm and a ship that wasn’t built to survive it.

These losses are significant. They point to a region that demands real respect from anyone navigating it. What they don’t support, however, is any claim of supernatural anomaly — no unusual magnetic disturbances beyond what active geology produces, no statistically elevated disappearance rate compared to other busy stretches of ocean with comparable weather and geography.

The National Oceanic and Atmospheric Administration has noted that regions like the Bermuda Triangle don’t show elevated incident rates when losses are measured against traffic volume. The ocean is dangerous. Concentrated shipping lanes in geologically active, typhoon-prone regions are especially dangerous. That’s the whole story.