The Long Blue Line: Coast Guard Cutters and WWI Convoys

Algonquin, Manning, Ossipee, Seneca, Tampa and Yamacraw. One hundred years ago, these were the six Coast Guard cutters selected for overseas ocean escort convoy duty during the United States’ participation in WWI. With the U.S. declaring war on Imperial Germany on April 6, 1917, the Coast Guard was assigned to the jurisdiction of the U.S. Navy for the duration of the war. Chosen for their long-range cruising capabilities and larger size, these cruising cutters were instructed to report to various east coast naval shipyards in New York, Boston, Virginia, and Charleston, South Carolina. After being rearmed and refitted for overseas service, they sailed for the British naval port of Gibraltar, and upon arrival, attached to Division 6, Patrol Squadron 2, Base 9.

The North Atlantic naval convoy system was introduced by the British Admiralty in May 1917 in response to staggering allied shipping losses caused by German U-boats in that maritime region. Upon arrival in European waters, the six cutters’ main objective was to protect transatlantic and oceanic commerce through German submarine infested waters between Gibraltar, England, and Mediterranean ports. German U-boats operated out of the ports of Wilhelmshaven and Kiel, Germany, and were highly aggressive in their offensive against allied shipping in the North Atlantic and British home waters. U-boats sank roughly 5,000 allied ships during WWI. What the cutter captains and crews could see above the water wasn’t nearly as deadly as what they couldn’t see beneath the water.

The Ossipee, skippered by Capt. William Munter, was the first cutter to arrive in Gibraltar on Aug. 30, 1917, and the Tampa, commanded by Charles Satterlee, was the last to arrive late on Oct. 26, 1917. Upon arrival at Base 9, several of the cutters were initially assigned as convoy escorts through British home water “danger zones” which were highly active patrol areas for German U-boats. After a few days of danger zone duties, each cutter was assigned as ocean escort for an outgoing convoy.

Convoy duty was difficult, dangerous, and monotonous. The typical convoy consisted of anywhere from six to more than 40 merchant steamers. Some of these ships were professionally operated by British Royal Navy crews while others were in terrible shape and crewed by novices. Unable to move faster than the slowest merchant ship in the convoy, usually anywhere from seven to 10 knots for about 11 days straight, they sailed in a zigzag pattern, in columns spaced four to 800 yards apart and at least 400 yards between ships in each column. At night, they sailed dark in order to avoid detection and torpedoes.

Algonquin, Manning, Ossipee, Seneca, Tampa and Yamacraw were the lone escort ships in the majority of their many convoys. They had to ensure each vessel stayed on formation and maintain awareness of their surroundings- particularly in the danger zone areas nearer to British ports. Avoiding collisions with other vessels in the same convoy was a top concern- particularly in foggy or rough seas. Every ship in a convoy relied on each other to keep an eye out for, and report on any submarine activity in the immediate area. When an alarm went off for a submarine sighting, general quarters was called, and the cutter’s responsibility would be to swing around full speed to where the submarine was last sighted, and if possible, attack the sub by shooting at it or dropping depth charges with the hope of sinking it- or at least forcing it to submerge and slink away. A fully submerged German submarine was blind and mostly ineffective.

The six American cutters had many run-ins with U-boats and their torpedoes. Rescuing survivors of torpedoed ships was risky and not encouraged, however, Seneca, captained by William Wheeler, actively participated in three daring rescues of the torpedoed convoy vessels- HMS Cowslip, and steamers Queen and Wellington. In each instance, the crew of the Seneca exhibited great valor and courage under harrowing conditions – saving the lives of crew members aboard the sinking ships and those floating in rough seas. The Seneca ran 30 convoys and escorted 580 ships during its acclaimed WWI service.

Algonquin (Capt. George Carmine), Manning (Capt. A.J. Henderson), Ossipee (Capt. William Munter), and Yamacraw (Capt. Randolph Ridgely, Jr.) had similar experiences as that of Seneca during the war. They sighted and attacked U-boats, were directly attacked, and had a number of near misses with torpedoes, in addition to saving survivors of sinking convoy ships. Algonquin escorted 19 convoys, Manning escorted 31 convoys of approximately 550 ships- sustaining no losses. Ossipee participated in 32 convoys overall, and was the ocean escort for 23. Yamacraw severely damaged (or actually sank) one submarine, convoyed close to 700 ships, and cruised a total of over 36,000 miles.

Tampa (Capt. Charles Satterlee), which escorted 19 convoys with only two losses in one year’s time overseas, was the only cruising cutter torpedoed and sunk on Sept. 26, 1918. UB-91, returning to its homeport in Germany, came upon Tampa, alone, having just detached from its 19th convoy. Tampa was headed toward the British port of Pembroke Docks in Wales, when UB-91 fired its last torpedo and hit Tampa amidships, causing at least two major explosions and sinking the cutter within three minutes. One hundred thirty-one crewmen and British passengers perished- making it the Coast Guard’s single worst loss of life during that conflict.

These six cutters and their brave crews stood a difficult, dangerous and, at times, monotonous convoy duty. They exhibited valor and courage, experienced harrowing conditions and loss, but at all times, they lived up to the service’s core values of honor, respect and devotion to duty.