Skip Navigation


Security Levels

Thetis, 1931


The cutter Thetis was named for a sea nymph of Greek mythology.  She was the daughter of the sea god Nereus and the mother of the Trojan War hero Achilles.

Builder: Bath Iron Works, Bath, Maine

Launched: 9 November 1931

Commissioned: 1 December 1931

Decommissioned: 1 July 1947

Disposition: Sold, 1 July 1948

Displacement: 1933: 337 tons full load
                          1945: 350 tons full load

                       Length: 165' oa
                       Beam: 25' 3"
                       Draft: 7' 8" (1933); 10' (1945)

Machinery: 2 x Winton Model 158 6-cylinder diesels; 1,340 bhp

Propellers: twin, 3-bladed

Performance: Maximum speed: 16.0 knots
                        Maximum sustained: 14.0 knots for 1,750 statute miles
                        Cruising: 11.0 knots for 3,000 statute miles
                        Economic: 6.0 knots for 6,417 statute miles

Complement: 1933: 5 officers, 39 men
                        1945: 7 officers, 68 men

Armament: 1933: 1 x 3"/23; 1 x 1-pounders;
                    1941: 1 x 3"/23; 1 x Y-gun; 2 x depth charge tracks;
                    1945: 2 x 3"/50 (single-mounts); 2 x 20mm/80 (single mounts); 2 x depth charge tracks; 2 x Y-guns; 2 x Mousetraps.

Electronics: 1933: none
                     1945: Radar: SF; Sonar: QCO 

Cost: $208, 569.90

Class History:

The 165-foot "B" Class cutters, sometimes referred to as the Thetis-Class, were a follow on to the 125-foot cutters.  Both types of cutters were designed for the enforcement of Prohibition, but the 165-footers primary mission was to trail the mother ships that dispensed alcohol to smaller, faster vessels well beyond the territorial waters of the U.S.  Hence these cutters had to have excellent sea-keeping qualities, good accommodations for the crew, and long range.  Although Prohibition ended soon after most entered service, their design nevertheless proved to be adaptable to the many other missions of the Coast Guard.

An article written soon after they entered service noted that: "the new cutters are low and rakish, without excessive superstructure or freeboard.  A raking stem, well flared bow and cruiser stern give the appearance of speed as well as contribute to the seaworthiness of the vessels, a quality which has been demonstrated in actual service. . .The new ships are twin-screw driven by two 670 horse power Diesel engines, furnished by the Winton Engine Co. of Cleveland, Ohio.  The shafting and propellers are arranged and supported in a novel manner.  The ship is equipped with two overhanging rudders on a line with and just aft of the propellers.  The rudders are supported by a streamline rudder post at the forward end which is bossed out for a bearing to take a stub shaft which extends through the propeller.  This method of arranging the rudders has proved remarkably successful.  At full speed, the ships turn a complete circle in two minutes and eighteen seconds, and can be docked with ease under the most difficult conditions.  On trial runs, the Atalanta averaged 16.48 knots at 468 RPM with practically no vibration and the engine under no evident strain.  Due to the arduous service for which these vessels were built, only the finest materials available were used. . .It is interesting to note that genuine wrought iron pipe was used for practically all the services where resistance to corrosion, vibration, and strain was required.  The fuel oil, lubricating oil, and water service to the main engines and auxiliaries; the fire and bilge system; and the steam heating system were all installed with genuine wrought iron pipe.  At the Lake Union plant this pipe was furnished by the Reading Iron Company through the Crane Company's Seattle office and Bowles Company of Seattle.  The new ships are a distinct contribution to modern shipbuilding and should be of great value to the Coast Guard."*

They certainly did prove to be of great value to the Coast Guard.  Most saw service as coastal convoy escorts during World War II and two, the Icarus and the Thetis, each sank a U-boat.  Many saw service well into the 1960s and some still service as tour boats in New York City with the Circle Tour Line, testament to their sturdy and well-thought out design.


The Thetis--a twin-screw, diesel-powered, steel-hulled Coast Guard patrol boat was laid down on 9 May 1931 at Bath, Maine, by the Bath Iron Works Corp.; launched on 9 November 1931; and delivered to the Coast Guard on 27 November 1931.  She was accepted for service two days later.

Assigned to Division 2, Destroyer Force, on 30 November, Thetis departed Bath on 1 December for shakedown training off the eastern seaboard.  During this cruise, she visited Washington, D.C.  Subsequently she was transferred to the Special Patrol Force of the New York Division, the ship was stationed initially at Stapleton, New York.

By 1934, the vessel had apparently been transferred to Boston.  She remained on duty there through July of 1940.  In mid-1941 found Thetis shifted south to Key West, Florida.  As one of the six ships of her class taken over by the Navy, Thetis was assigned to the East Coast Sound School, Key West, on 1 July 1941, concurrently with the establishment of the four Sea Frontiers.  By late 1941, the Coast Guard patrol boat was assigned collateral duties in the Gulf Patrol, a unit of Task Force 6.  Other ships in this group included Destroyer Division 66, Subchaser Division 31 (less PC-451), and three of Thetis' sister ships.

Attached to the Sound School at the time of the Japanese attack on Pearl Harbor on 7 December 1941, Thetis was classified WPC-115 sometime in or around February of 1942.  At about this time, early 1942, German U-boats experienced what they considered a "happy time" off the eastern seaboard, as American vessels were not yet being escorted from place to place. American antisubmarine measures were largely crude and ineffective for nearly the first four or five months of World War II.

On 9 June, while in the course of carrying out her normal training and patrol missions off the east coast of Florida, Thetis took part in an unsuccessful search for what was suspected to be a U-boat.  However, the torpedoing of the American freighter Hagan on the evening of 10 June 1942 gave the American "hunter killer" forces something unquestionably real to hunt for.  She was U-157, and Hagan had been her first victim, being damaged but not sunk by the U-boat.

Accordingly, a "dragnet" was thrown out to find and destroy the submarine before she could attack any other ships.  This intensive search effort involved radar-equipped Army B-18 bombers, three destroyers, several PC's, and Thetis' sister ship, Triton (WPC--116).  On 13 June, Thetis picked up a definite contact and plunged ahead for the kill.  With the unseen target 200 yards two points on the port bow, Thetis went to general quarters and continued ahead about 1,000 yards before turning to port and increasing to full power.  Regaining contact upon steadying out on her base course--she had temporarily lost it while maneuvering --Thetis bore down on the U-boat.

The patrol craft dropped her first depth charges at 1558--five charges set for 200 to 300 feet at five-second intervals.  She also launched a further two from the ship's "Y" gun at the time of release of the third charge.  After making the run and observing the explosions, Thetis turned to starboard to observe the results of her attack, and observed a "water slug" (a disturbance in the water) a short distance to the right of her own wake.  As the commanding officer of Thetis observed, the "slug" did not resemble the disturbance usually associated with the explosion of depth charges.

Thetis observed pieces of freshly broken wood float to the surface at 1618, as well as articles of clothing.  Thetis then maneuvered into the flotsam and jetsam and retrieved two pairs of leather submariner's pants of the type usually worn by U-boaters in the northern latitudes.

PE--27 soon made an approach and dropped a marker buoy.  Thetis, meanwhile, sighted and picked up a tube of lubricant made in Dusseldorf, Germany.  While Thetis returned to rearm at Key West, PE--27, PC--519, and Triton all carried out attacks--all in actuality unnecessary as Thetis had already sunk the U-boat on her first run.  Thetis came back and conducted one more attack, but U--157 had already gone to the bottom, entombing her crew in her hull. 

On 7 January 1944 she rescued 7 survivors from the USS St. Augustine (PG-54).  She was assigned to Air-Sea Rescue duty in the Third District in June, 1945.  She returned to Coast Guard jurisdiction after World War II and served until 1947.  She was decommissioned on 1 July 1947 and was placed in storage at the Coast Guards Cape May Moorings.  She was sold on 1 July 1948 to the Southeastern Terminal and Steamship Company.


Cutter files, USCG Historian's Office.

Canney, Donald L. U.S. Coast Guard and Revenue Cutters, 1790-1935. (Annapolis, MD: Naval Institute Press, 1995).

Dictionary of American Naval Fighting Ships, Vol. VII - p 135.

*Nickum, W. C. "New 'Sisters' of the Coast Guard Patrol Go Into Service."  The Reading Puddle Ball 3, No. 11 (February 1935), pp. 6-7. 

Scheina, Robert L. U.S. Coast Guard Cutters and Craft in World War II. (Annapolis, MD: Naval Institute Press, 1982).

U.S. Coast Guard. Public Information Division. Historical Section. The Coast Guard at War: Transports and Escorts. (Vol. V, No. I). (Washington, DC: Public Information Division, U.S. Coast Guard Headquarters, 1949.

Last Modified 1/12/2016