The USS Denebola (AD-12) was a destroyer tender stationed in Portland Harbor from 1941 to 1944. Contributed / South Portland Historical Society

South Portland Historical Society will hold its next lecture on Thursday, Jan. 16, at 6:30 p.m. at the South Portland Community Center, 21 Nelson Road. Matthew Christoforo, society board member and historian, will present “Defending Casco Bay during WWII.” The event is free for current members of the society; non-members may attend for $20.

Christoforo’s lecture will cover the role of Casco Bay within the larger narrative of World War II, the challenges faced by the existing defense infrastructure, as well as the geographic challenges of defending the bay with its many points of access. The lecture will also include some visual displays, including a demonstration of an original WWII blackout bulb.

The Greater Portland area, the harbor and the islands were buzzing with military activity during World War II. Of course, here in South Portland, we talk frequently about our two shipyards where we built 274 Ocean and Liberty-class cargo ships during the war. Compared to most other ports along the east coast, Portland was closest to Europe and the convoy lines.

Portland Harbor became the departure point for North Atlantic convoys transporting supplies to our European allies. In 1941, Rear Adm. Ferdinand Reichmuth, COMDESLANT (Commander, Destroyer Force, Atlantic), moved his headquarters to Casco Bay. Portland Harbor became a major anchorage for the U.S. Atlantic Fleet. Throughout WWII, destroyers, destroyer escorts and other support ships were anchored all over the harbor. We even had some aircraft carriers stop in Casco Bay during the war.

With the Naval station headquartered in Portland, the Coast Guard base in South Portland serving as the anti-submarine net depot, coastal defense activities at Fort Preble and Fort Williams, the fuel depot on Long Island, the Navy barracks and Fleet Training Center on Great Diamond Island, and a myriad of other military installations and operations around the area – life was very different in Greater Portland during the war.

It’s hard to fathom the amount of food, fuel, and raw materials that were transported here – for the people, the Liberty ships, and to supply the vast fleet in the harbor. In addition, the large number of newly constructed and/or newly commissioned ships, along with their new crews, received training and were taken on shakedown cruises in Casco Bay to prepare them.

All of this activity was heavily protected. Our coastal defenses included anti-submarine nets, minefields, hydrophones and magnetic loops. The threat of attack by German U-boats was real. Local fishermen found their jobs severely impacted, as the military had control of the harbor and all of the activities in it. In order to continue fishing, they had to apply for and receive special identification, and had to follow all restrictions placed on them related to where they could and could not fish. Recreational boating was not allowed in the harbor.

There were some interesting ships in service in Portland Harbor during WWII. One was the USS Denebola (AD-12), a destroyer tender. Prior to WWII, the Denebola had been out of commission for many years, but was recommissioned in 1940 and became the flagship of the Commander of the Atlantic fleet of destroyers. Early in 1941, she was based in Norfolk, Virginia, but she arrived here with COMDESLANT in September of 1941, before the attack at Pearl Harbor, and remained in Portland Harbor supplying the destroyers and other ships here until July of 1944. The Denebola also provided repair and maintenance services to the Navy ships.

Another interesting ship here during the war was USS Nantucket (LV-112). Formerly (and later) known as the Lightship Nantucket, the ship had previously been serving at Nantucket Shoals. In 1942, it was pulled from lighthouse service, painted gray and outfitted with a 20 mm gun, and served as an armed examination vessel at the entrance to Portland Harbor. The USS Nantucket patrolled the area and could detect incoming ships from as far away as 8 miles.

Casco Bay Lines was also affected during the war. The Navy took the CBL steamboat SS Aucocisco in 1942 and renamed her the SS Green Island (YFB 32). The Green Island served as a ferry, carrying service members between Portland and the many ships moored and anchored around Casco Bay. When the war was over, she was returned to CBL and her name was changed back to Aucocisco.

The South Portland Historical Society hopes you will join us in the Casco Bay Room at the South Portland Community Center on Thursday, Jan. 16, at 6:30 p.m. for the illustrated lecture on “Defending Casco Bay during WWII.” The lecture is free for our members, $20 for non-members. Annual family memberships will be available for $25 at the door. Please arrive early if you wish to join. The South Portland Community Center is handicap accessible. The lecture is brought to you with the generous financial support of Bristol Seafoods, with the additional support of Saco and Biddeford Savings Institution. For more information, the historical society can be reached at 207-767-7299 or by email at sphistory04106@gmail.com.

Kathryn Onos DiPhilippo is executive director of the South Portland Historical Society.