dp. 1870 (surf.), 2424 (subm.); l. 312'; b. 27'; dr. 15'3" (mean);
s. 20.25 k. (surf.), 8.75 k. (subm.); a. 1-5"/25; 6-21" tt. fwd., 4-21" tt. aft..;
cpl. 6 officers - 54 enlisted men; cl. GATO

Keel laid by the Manitowoc Shipbuilding Company, Manitowoc, WI 5 May 1943;
Launched 24 October 1943; Sponsored by Mrs. Robert W. Berry;
Commissioned 1 March 1944; Lcdr. John C. Martin in command;
Decommissioned 10 May 1946; Recommissioned 6 February 1952;
Decommissioned 22 May 1952; Recommissioned 16 July 1954;
Decommissioned and loaned to Turkey 7 August 1954; Returned, struck and sold to Turkey 1 January 1972.

After a month's training in Lake Michigan USS HAMMERHEAD I (SS-364) was placed in a floating drydock and towed down the Mississippi River to New Orleans, La., where she arrived 8 April 1944. She subsequently proceeded to Balboa, Canal Zone, for further training, and thence to Pearl Harbor, Hawaii.

The submarine departed Pearl Harbor on her first war patrol 6 June 1944 in company with USS STEELHEAD (SS-280) and USS PARCHE I (SS-384). Cruising the seas south of Formosa, her first engagement came 9 June when she sank a sampan with gunfire. She then encountered a coastal oiler 29 June and closed for the attack, but the torpedoes failed to strike home and a surprise aerial attack forced the sub down. Next day HAMMERHEAD damaged several ships of a convoy. She returned to Fremantle, Australia 17 August 1944.

HAMMERHEAD's second war patrol was conducted in the Java and South China Seas. She departed Fremantle 9 September and made her first attack the night of 1 October, when a convey consisting of four cargo ships, one oiler, and three escorts was detected off Borneo. HAMMERHEAD fired 10 torpedoes, scored a total of 6 hits and sent 3 of the cargo ships to the bottom. The morning of 20 October the submarine found still another six ship convoy, and after evading one of the escorts delivered a six-torpedo attack. Two more cargo ships fell victim to HAMMERHEAD's marksmanship. The submarine returned from this highly successful patrol 2 November 1944, and was later awarded the Navy Unit Commendation for outstanding performance. The submarine commenced her third war patrol 25 November, returning to the South China Sea. On the cruise she operated with USS LAPON I (SS-260) and USS PADDLE (SS-263), and although several attacks were made, no sinkings resulted. She returned to Fremantle 17 January 1945.

HAMMERHEAD departed on her fourth war patrol 19 February, in company with USS BAYA (SS-318). Patrolling off Cap Varella, she detected a convoy and two escorts 23 February and while closing the cargo ships obtained a perfect shot on an escort. A spread of four torpedoes sank Japanese frigate YAKU. Due to the illness of her commanding officer, the submarine was forced to end her patrol, and moored at Subic Bay 3 March 1945.

Beginning her fifth war patrol 10 March 1945, HAMMERHEAD proceeded to the coast of Indochina, where on 21 March she detected a large escorted convoy. Working her way inside the screen, the submarine was able to get a clear shot at an escort vessel, and a single hit broke her in two. After sinking the escort, HAMMERHEAD damaged other members of the group before retiring. She returned from this war patrol 6 April 1945, mooring at Subic Bay, Philippines.

For her sixth war patrol HAMMERHEAD operated in the Gulf of Siam. She arrived 6 May and that night encountered a small tanker and two escorts. After missing with two torpedoes at extreme range the submarine found the mark in a second attack, sinking the tanker. HAMMERHEAD attacked other ships of the convoy without success and after a depth charge attack decided to break off. Sighting a cargo carrier 14 May with only an aircraft escort, HAMMERHEAD made a perfect approach and sank the ship with two torpedoes. She returned from this patrol 25 May.

HAMMERHEAD departed Fremantle 21 June on her seventh and last war patrol, also carried out in the Gulf of Siam, in company with three other submarines. Her major attack of this patrol occurred 10 July, when she sank cargo ships. The patrol was brought to a close 21 August 1945 at Pearl Harbor.

HAMMERHEAD arrived Mare Island, Calif., 20 August 1946 and was decommissioned 10 May1946. She was then placed in the Fleet Reserve at Mare Island. Subsequently, HAMMERHEAD was brought out of reserve during the Korean conflict, recommissioned 6 February 1952, and engaged in training duty on the West Coast between San Diego and San Francisco, Calif. until 22 May 1952, when she decommissioned for return to the Reserve Fleet. Earmarked for loan under the Military Assistance Program, the veteran submarine recommissioned once more 16 July 1954 to prepare for transfer. Decommissioned and transferred to Turkey 7 August 1954, where she served the Turkish Navy as CERBE (S-341) until she was returned, struck and resold to Turkey on 1January 1972.

HAMMERHEAD received seven battle stars and a Navy Unit Commendation for World War II service. All seven of her war patrols were designated successful.