Most Americans think World War II took place on some other continent – “over there” – either Europe or the Pacific. Few realize enemy action took place a few miles off shore. But 66 years ago today, a German submarine even mined Boston Harbor.

Most Americans think World War II took place on some other continent – “over there,”  either Europe or the Pacific. Few realize enemy action took place a few miles off the East Coast. But 66 years ago today, a German submarine even mined Boston Harbor.

Germany declared war on the United States on Dec. 11, 1941, four days after Japan attacked Pearl Harbor. Nazi submarines (also called U-boats) struck the U.S. East Coast in early January 1942 and sank Allied ships at the rate of one every four hours. During the first six months, 500 ships were sunk in the western Atlantic.

On June 12, 1942, the U-87 crept into Boston Harbor and mined the entrance. Luckily, because of poor placement, no ships were sunk. However, the sub sank two ships off Provincetown, killing 93 men. U-boats also mined the waters of New York, Chesapeake Bay and Florida.

New England and the rest of the country were ill prepared for the first U-boat attacks. In terms of ships sunk and lives lost, the beginning of the “Battle of the Atlantic” was a greater disaster than Pearl Harbor. New England lost nine ships during the early months of battle.

Horst von Schroeter, former watch officer of the U-123, remembers the action off the U.S. coast during 1942 as a time of anguish as well as elated victory. “I remember the night we sank two tankers in a very short time, perhaps within one hour,” said von Schroeter.

“There was no special danger or risk present. No anti-submarine defense to prevent us from sinking those poor ships that ran into our torpedoes. I think for men going to sea, it was always a terrible sight to see a ship sinking. Never mind if it was our intention or an accident. But on the other hand, it was our job, our duty to sink ships.”

Losses decreased after August 1942 when American cities enforced blackouts, radio communication was controlled and the convoy system put into operation. The Hingham Naval Ammunition Depot and Cohasset Annex became the major source of ordnance for the Navy’s Atlantic Fleet.

The “Depot” worked shifts around the clock to meet war’s demands. Veteran George Bartlett of Hingham reflects back to his homeland security duties, “I started out the war as a coastal observer and shore guard. After that, I transferred to Ordnance at the Annex. We all did our part. I remember seeing one sub in 1943 prowlingthe waters off Brant Rock looking for prey. As soon as I gave the alert, it disappeared. U-boats were always on the prowl. Boston Harbor and the depot perimeter were constantly patrolled by guard boats and watchmen looking for any security breaches.”

“The Depot was a beehive of activity during the war.," recalled Anna Cookson of Plaistow, N.H., who worked in administration at the Depot. "There were over 2,000 civilians and 1,100 sailors and marines involved there. Security was tight and safety was paramount. Civilian planes weren’t allowed to fly over the depot. We always met or exceeded our production quota on time.”

Hingham’s Louise Mabel recalls some of the demanding work,.

“I loved working at the Annex. I not only assembled rockets and detonators but also worked as a welder. The women were just as good as the men getting the ammo out. We also provided ordnance for the British. I made a lot of great friends here and worked nights as well as the day shift.”

The tide turned against U-boats in 1943 when more effective anti-submarine tactics and weaponry were introduced. By 1944, more U-boats were sunk than merchant ships.

Not only did the enemy sink ships, but they also landed spies. The U-1230 sent ashore two intelligence agents inside Bar Harbor, Maine at Hancock Point on Nov. 29, 1944. Their mission was to disrupt the Manhattan Project (atomic bomb) and gather information. The saboteurs were caught the following month but the sub did manage to torpedo and sink the Canadian freighter Cornwallis off Mount Desert Rock, Maine, killing 44 of its crew. Enemy agents were also put ashore on Long Island and Florida.

Even to war’s end, U-boats patrolled New England waters hunting for Allied ships. On April 23, 1945, the U-853 sank the sub chaser USS Eagle five miles off Cape Elizabeth, Maine, killing 49 sailors.

On May 5, 1945, three days before Germany surrendered, the U-853 also sent to the bottom a coal freighter Blackpoint two and a quarter miles off Point Judith, Rhode Island, killing 12 crewmen. The following day, the U.S. Navy sank the U-853 with all hands on board in Block Island Sound.

Today, sport divers frequently explore the wrecks of the U-853 and Blackpoint. During a 2002 survey of the Blackpoint’s remains, a local scuba diver found a five-inch shell for the stern-mounted deck gun. An ammunition inspection certificate from the Hingham Naval Ammunition Depot  floated out of the shell after being separated from the projectile. Arming the merchant fleet by the Navy shows the high level of threat to the U.S. coast during that time.

World War II cost Germany two thirds of its 1,162 U-boats and 28,962 of the 39,000 sailors who manned them. U-boats sank 13 ships off New England that resulted in 254 deaths and 457 rescued. U-boats sank a total of 2,979 merchant ships during the war, killing more than 6,000 American and 30,000 British mariners.

Retired Air Force Lt. Col. Jim Rose of Hopkinton is the historian and editor of Wompatuck News, the newsletter of the Friends of Wompatuck State Park in Hingham, a volunteer organization that helps maintain the park. For information about joining, call 781-749-0072.