More details on mystery mine found floating in Puget Sound

The Navy says a mine floating near the Brownsville marina on Tuesday was an inert training mine from an exercise back in 2005. It was a demonstration of new unmanned underwater vehicle technology, with the capability to detect underwater objects and avoid submerged obstacles.

Navy crews are now surveying the area around Brownsville and Keyport to recover any other remaining training mines.

As for details about the mine, Seattle historian Feliks Banel says it’s tough to analyze now that it’s in pieces. Crews blew it up Tuesday night.

RELATED: Crews detonate ordnance found floating in Puget Sound

The theory is it might be a Mark 6 moored contact mine, not to be confused with a Mark 5 or a Mark 7.

“It has about a 34-inch diameter,” Banel said. “I’ve seen pictures of a Mark 6 moored contact mine and it looks very similar to this one, but I can’t tell the scale of the one they blew up. Because again, they blew it up.”

Banel said he has reached out to the Naval History Heritage Command in Washington D.C. but they were unprepared to address questions about the mine and its potential 75-year-old history.

“This Mark 6 design originally goes back to 1917 and they were still making them as late as 1978… They (the US Navy) were still using these in the 80s.”

It wouldn’t be far fetched for the Navy to be using these mines in the region during World War II, according to Banel.

“The theory was, in the immediate aftermath of Pearl Harbor, that there might be Japanese aircraft carriers off the coast, they can use radio station signals as a homing beacon,” Banel said. “Basically, we didn’t know how World War II was going to turn out and we had to defend Puget Sound and all these U.S. ports.”

Banel says the military laid about 20,000 defensive mines in U.S. waters during World War II. The Seattle Times, on Dec. 8, 1941 reported it’s unclear if the military was laying harbor mines in the Puget Sound, the way they were in San Diego.

The Navy would also string up nets or gates across waterways. Banel said his friend, Ron Burke, born in 1931, remembers riding a ferry from Bremerton to Seattle as a 10-year-old. He recalled there being a gate or net across the water near Rich Passage. A boat would come out to meet the ferry to open and close the gate. It was meant to keep submarines from getting to the naval shipyard.

Of course, those gates were not explosive like a mine.

“I’m not convinced of how many mines were actually laid in Puget Sound during World War II,” Banel said. “It seems they would have in some key places where they couldn’t defend it any other way, but we don’t know that.”

So is it possible there are more mines across Puget Sound?

The Navy confirmed that only some of the training mines were buoyant and not all of them were recovered in the area near Brownsville, Keyport, and Bainbridge Island.

Banel jokingly recommended brushing up on your Gilligan’s Island if you’re worried.

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