Corsair Fleet: The Brave Civilians Who Took On German U-Boats to Protect the US Coastline

Photo Credit: Bettmann / Getty Images
Photo Credit: Bettmann / Getty Images

While many know the story of the “Little Ships of Dunkirk,” Great Britain wasn’t the only nation to call upon every day citizens to come to their nation’s aid in a time of need. In early 1942, the US military was facing a crisis: it had a massive coastline to protect from German U-boats and nowhere near enough vessels to do so. This led to the creation of the civilian-involved Corsair Fleet, a unit underneath the umbrella of the US Coast Guard.

Looking for a solution to the German U-boat threat

Military portrait of Fleet Adm. Ernest J. King
Fleet Adm. Ernest J. King. (Photo Credit: United States Navy / Naval History and Heritage Command / Wikimedia Commons / Public Domain)

In 1941, Alfred Stanford, commodore of the Cruising Club of America, offered his ships and crews to Adm. Ernest J. King, chief of naval operations. King, however, was a traditionalist and immediately dismissed the idea of civilians hunting for German U-boats.

The yachtsmen didn’t relent and created a public outcry. After numerous letters and newspaper articles called for the use of these vessels and their crews, King finally gave in and put the volunteers under the command of the Coast Guard, due to the branch’s experience with the Auxiliary, a force made up of those too old, young or unfit to fight.

The Coast Guard Auxiliary usually featured unpaid volunteers, but could temporarily employ paid members for its main fighting force. In 1941, it stood around 7,500 members and had 2,000-3,000 craft, most of which were only suitable for inland or coastal operations. The Auxiliary’s main duty was to supplement the Coast Guard’s main force, assist with safety inspections, perform lifesaving efforts, and patrol coastal beaches for spies and saboteurs.

Establishment of the Coast Picket Force – AKA Corsair Fleet

Corsair Fleet insignia, featuring Donald Duck
Corsair Fleet Insignia, featuring the Disney character Donald Duck. (Photo Credit: U.S. National Archives / Unrestricted Use)

In May 1942, the Coastal Picket Force (CPF) was established. The CPF was designed to use auxiliaries and their ships as a screen, to keep German U-boats from gaining access to the coastal shipping of the eastern United States. However, organizing a such a large force proved too much for untrained civilian volunteers, and the foolhardy adventurers were put under direct control of the Coast Guard. 

The sailors, fishermen and yachtsmen had what they wanted: approval for, and a method to create, a fleet of sailing and motor yachts, which could take the fight directly to the U-boats. While officially known as the CPF, they more-commonly went by the moniker, Corsair Fleet.

Layout of the Corsair Fleet

Painting of a yacht with the Corsair Fleet at sea
Painting depicting a yacht manned by the Corsair Fleet on U-boat patrol off the coast of Newfoundland. (Photo Credit: U.S. National Archives / Unrestricted Use)

The Corsair Fleet was divided into six groups, from the north Atlantic down to Florida. Manned by crews made up everyone from college students to experienced and skilled fisherman, the picket ships patroled a designated square of 15 nautical miles along the 50-fathom line of the Atlantic seaboard. This often meant cruising more than 150 miles off the coast.

This came as a rude awakening for many of the less-experienced sailors, who were expecting relaxing summer cruises, not the rough seas of the deep Atlantic. However, the ships were sound and seaworthy, often the famous racing yachts of wealthy New Englanders or the fishing schooners of their blue collar counterparts. 

Upon arriving at base, each ship was stripped of its civilian embellishments and painted battleship grey, with a Coast Guard designation. That being said, this was as far as military discipline and uniformity went in this ragtag group of foolhardy men.

Hunting German U-boats off the US East Coast

Crew standing atop a German U-boat
German U-boat, 1939. (Photo Credit: Bettmann / Getty Images)

Despite their lack of decorum and military style, the ships of the Corsair Fleet proved to be effective at their task. The wooden-hulled sailing vessels were particularly useful. The U-boats’ advantage was their ability to submerge, but doing so limited their view. To supplement this, they used sonar to listen for other ships – something that worked in the CPF’s favor. A ship under sail makes little-to-no noise below the surface, unlike a diesel motor or steam engine. 

This made the CPF vessels much harder to detect, allowing them to get close to the enemy and gather a more accurate report on their position. The lack of noise pollution also allowed them to use sonar much more effectively. Though this backfired at times, one ship, Valor, called in an airstrike on a U-boat, which turned out to be their misidentified refrigerator engine.

The Corsair Fleet was highly effective

CGR-2502 and CGR-2520 on patrol at sea
Corsair Fleet schooners CGR-2502 and CGR-2520 on patrol for German U-boats. (Photo Credit: U.S. National Archives / Unrestricted Use)

Despite this lack of discipline or military skill, the ships proved to be highly effective. John Kimball, a carpenter on Actaea, shared one account of how effective they could be. While cruising, the crew located a German U-boat. They were faced with a difficult decision: break radio silence and give their position away or keep themselves safe while risking the rest of the American merchant fleet. 

The brave crew took the first choice and radioed in the submersible’s position. The entire crew huddled around the radio, not knowing what would happen next. To their surprise, the U-boat dove and fled. This proved to be a psychological shift for the German submariners along the East Coast. It was no longer open season – they were being watched.

Another instance showed the effectiveness of a line of Corsair Fleet ships, when four of them became involved in the sinking of a single U-boat. First spotted by CGR-1923, the vessel was next reported by CGR-2516. That evening, she was spotted by CGR 2503.

Finally, the U-boat’s position was picked up by a Civil Air Patrol (CAP) flight, which dropped a smoke bomb. The smoke was seen by CGR-4436, which sped to the location and dropped depth charges. An oil slick was seen, and this became the only possible kill by the CPF. 

This operation also exemplified the combined-arms method of U-boat hunting, which had proven so effective. By the time the German vessel was hit, she’d been chased by four CPF ships, five CAP aircraft, four US Navy aircraft, two Navy vessels and a Navy blimp. While it took a lot to sink a single submersible, doing so likely saved scores of lives and hundreds of tons of precious cargo or fuel.

The Corsair Fleet didn’t just hunt German U-boats

CGR-2520 and another vessel on patrol at sea
Corsair Fleet schooner CGR-2520 and another vessel patroling for German U-boats. (Photo Credit: U.S. National Archives / Unrestricted Use)

The Corsair Fleet didn’t just there to hunt U-boats – the ships often assisted in rescues and retrieving lost cargo. The USS Pioneer rescued the crew of the tanker ST R.M. Parker Jr. when she was torpedoed in late 1942, while CGR-355 was able to recover much of the ordnance from the freighter SS Benjamin Brewster around the same time.

By the end of 1943, the U-boat threat had significantly diminished and, along with it, the need for the CPF. The operation was severely downsized, but not disbanded until the end of the Second World War.

It’s difficult to say exactly how effective the CPF was, as its ships had no confirmed kills. That being said, it did become clear they won on the psychological front. Their presence off the East Coast meant U-boat crews knew they couldn’t safely cruise the surface at night. On the flip side, the merchant seamen the Germans were targeting knew that, if they sank, there was likely a CPF ship nearby that would rescue the survivors.

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The story of the Corsair Fleet has, for the most part, faded into distant memory. However, their ability to bring the fight directly to the German U-boats not only broke the myth of a submersible’s invulnerability while cruising, but proved to be a useful deterrent for any enemy ship wanting to torment American shipping lanes.

Gabe Christy

Gabe Christy is one of the authors writing for WAR HISTORY ONLINE