Groton — Tired of the typical re-enlistment ceremony held in an office somewhere, Michael Roy decided he'd request a more unusual location.

Roy, a boatswain's mate first class at Coast Guard Station New London, said he wanted the ceremony when he signed on for six more years of service to be aboard a submarine. After all, he'd driven the station's boat during hundreds of submarine escorts since arriving at there in 2009.

Escorting submarines, Roy said, is "our job. It's 80 percent of what we do here."

The commanding officer of the Naval Submarine Base and the commander of the Coast Guard station both said they could not remember a time in recent years when a local Coast Guardsman re-enlisted aboard a submarine.

But on the deck of the USS Hartford Wednesday, Roy raised his right hand and swore to support and defend the Constitution. His wife, Stevana, and daughters, Natalie, 5, and Carlie, 3, stood nearby. After the swearing in they were led inside for a tour; it was the first time the family had been inside an operational submarine.

"It looks a little bigger when you're standing on it instead of following it in the boat," said Roy, 32, who has been in the Coast Guard for 14 years.

Lt. Todd Hartfiel, commander of Coast Guard Station New London, administered the oath. He said that while it was not Roy's intention, events such as this one help bring the two services closer together.

"It's building that brotherhood of sailors," Hartfiel said. "We're Coast Guard. They're Navy. But we're all shipmates."

Capt. Marc Denno, commander of the sub base, said the ceremony did demonstrate the strong ties between the services locally. The Coast Guard presence is much larger in southeastern Connecticut than in other places because of the Coast Guard Academy, he said.

Denno participated in another ceremony last month for a sailor who chose to re-enlist aboard the Coast Guard barque Eagle because of the ship's nautical heritage. He said he hopes to get more requests now from Coast Guardsmen who want to re-enlist at the Navy base.

"The relationship between the Coast Guard and the Navy, especially here in New London, is pretty unique," Denno said shortly before the ceremony. "Coast Guard Station New London provides security for the transiting of the boats. At the same time, with the large Coast Guard population, a lot of them live in our housing. We provide them medical care. And we work together closely in the community."

As members of the Military Superintendents Liaison Committee, Denno and Rear Adm. Sandra L. Stosz, superintendent of the Coast Guard Academy, work together on issues affecting military children. The next big event that will bring the Navy and the Coast Guard together, Denno said, is OpSail 2012, the bicentennial celebrations to commemorate the writing of the Star-Spangled Banner and the War of 1812.

"That involves the Navy and the Coast Guard up and down the Eastern seaboard to the Great Lakes," he said.