Diver Found Possible Inactive 1950 Nuke Off the Coast of British Columbia

The purported bomb was discovered by a man searching for sea cucumbers

Mark IV
A replica of the lost Mark IV nuclear bomb at the Royal Aviation Museum of Western Canada Royal Aviation Museum of Western Canada

Sean Smyrichinsky was zooming around on his underwater scooter near Pitt Island, located south of Prince Rupert, British Columbia, looking for sea cucumbers recently when he stumbled across something unusual. “I found this big thing underwater, huge, never seen anything like it before,” he tells John Mackie at the Vancouver Sun. “I came up telling all my buddies on the boat ‘Hey, I found a UFO. It’s really bizarre.’ And I drew a picture of it, because I didn’t have a camera.”

No one knew what to make of it until Smyrichinsky mentioned it to some local fishermen. They suggested something unexpected: he may have stumbled across a lost nuclear weapon. When he reached an area with internet access, the commercial diver began investigating the bombs and came across a photo of the insides of a 1940s-era nuclear device. “The picture I found has the bomb in sections, they’ve got it taken apart,” he said. “And in the middle, there’s a great big thing that looks just like what I found.”

Smyrichinsky emailed the Vancouver Sun and Canada’s Department of National Defence, describing the object. It was convincing enough that the DND is sending in a ship to secure the area.

James Griffiths at CNN reports that on February 13, 1950, a Convair B-36B American bomber was flying on a secret training run between Alaska and Texas to simulate a nuclear strike when something went wrong. The plane's wings iced up, and at least one of its six engines caught fire. The 17-man crew decided to ditch, but before they did they jettisoned a Mark IV nuclear weapon into the ocean.

George Dvorsky at Gizmodo reports that 12 of the crew members survived and parachuted onto Princess Royal Island. The others likely perished at sea. The plane was set on autopilot, eventually crashing into Mount Kologet many miles inland. Luckily, the Mark IV, a modified version of the famous “Fat Man” bomb that devastated Nagasaki, wasn’t functional.  The device was full of lead, uranium and TNT to make the training mission as realistic as possible, but lacked the plutonium needed to initiate a nuclear reaction, reports Griffiths.

Dirk Septer, a British Columbia aviation historian is not convinced that the “UFO” is the Mark IV. He tells Robin Levinson-King at the BBC that after the crash the United States military searched the wreckage and surrounding area for the bomb, afraid that it would fall into the hands of the Russians. Septer says from everything he knows about the flight and the search, Smyrichinsky’s object is in the wrong place.

Whatever Smyrichinsky saw will soon be clear—as Griffiths reports, the coastal defense ship HMCS​ Yellowknife is moving into the area and a submersible will investigate the site of the suspected bomb in the coming weeks.

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