Groton — The U.S. and Canadian militaries searched together for fake sea mines planted in the waters near Groton and Nova Scotia this week.
A homeland security drill, the exercise began when a fishing boat in Canada’s Sydney harbor triggered a simulated mine and “exploded.” Divers for both navies worked to clear the harbor.
They soon learned the “eco-terrorist” responsible had also laid fake mines near the Naval Submarine Base in Groton.
On Tuesday, divers with hand-held sonar looked for the metal objects shaped like mines in the Thames River. They would neutralize the mines by cracking the cases so water would flood in and destroy the electronics.
Earlier, unmanned undersea vehicles had collected sonar images of the area. Experts analyzed the imagery to distinguish the metal objects from the rocks, refrigerators, tires and old lobster traps that also can be found scattered along the river bottom.
The team in Canada had found 10 mines. Only a few remained near Groton.
U.S. Navy Capt. Dominic DeScisciolo, who oversaw the mine warfare portion of the exercise, said that while he didn’t think either military would encounter mines frequently, it’s “certainly within the realm of possibilities.”
“We need to be on our game and ready to respond and defeat this threat, wherever it may be,” he said from Nova Scotia during a phone interview.
In Groton, Cmdr. Brian Dulla said the divers he oversees from the San Diego-based Mine Countermeasures Division Three One often practice locating and detonating mines. But they typically don’t get the chance to work with other agencies, he said.
The exercise, “Frontier Sentinel 12,” which involved U.S. Fleet Forces, U.S. Coast Guard Atlantic Area and the Canadian Joint Task Force Atlantic, ends today. The drill has been held every two years since 2006.
“We have, for many, many years, worked together very effectively,” DeScisciolo said. “This gave us an opportunity to improve.”
Also on Tuesday, the Coast Guard practiced boarding a boat near Groton. The scenario suggested that the people on board would oppose them by force. Coast Guard Sector Long Island Sound established a unified command post to support the mine countermeasure exercise and trained the other agencies on their systems.
“These days, no one nation takes on a task by themselves,” Canadian Cmdr. Niall Hanratty said. “We rely on our partners in the U.S. and I’m sure they do on us. We support each other and get the job done when and where it’s required.”