, a Balao-class submarine, was the first ship of the United States Navy to bear the generic name for any fish, such as gar or marlin, with bill-shaped jaws. During World War II, Billfish made eight war patrols between 12 August 1943 and 27 August 1945. During these patrols she sank three Japanese cargo ships totaling 4,074 gross register tons and five smaller craft. She spent part of her seventh and eighth war patrols on lifeguard duty off Japan during Allied airstrikes.

Construction and commissioning Billfish was ordered on 15 December 1941.uboat.net Billfish (SS-286) Accessed 5 February 2023 Her keel was laid down at Portsmouth Navy Yard in Kittery, Maine, on 23 July 1942. She was launched on 12 November 1942, sponsored by Mrs. Lewis Parks (wife of Lieutenant Commander Lewis Parks), and commissioned on 20 April 1943 with Lieutenant Commander Frederic C. Lucas, Jr., in command.

Service history World War II April–August 1943 After her commissioning, Billfish began shakedown training off the United States East Coast. She arrived at Newport, Rhode Island, from New London, Connecticut on 24 May 1943, then, after torpedo trials at Newport, moved from Newport back to New London on 28 May. She was on the slipway at New London from 19 to 22 June 1943.

On 24 June 1943, Billfish got underway from New London bound for Cristóbal in the Panama Canal Zone, which she reached on 2 July 1943. She transited the Panama Canal on 6 July 1943, and departed Balboa, Panama Canal Zone, the same day bound for Brisbane, Australia, to deploy to the South West Pacific Area. She reached Brisbane on 1 August 1943.

From 8 to 10 August 1943, Billfish conducted antisubmarine warfare exercises off Brisbane with the Royal Australian Navy destroyer and Royal Australian Air Force aircraft. After Vendetta parted company with her on 10 August to make for Moreton Bay, Billfish remained at sea for one more day of exercises on 11 August before returning to Brisbane.

First war patrol Billfish departed Brisbane on 12 August 1943 for her first war patrol. The Royal Australian Navy Motor Launch escorted her into Darwin, Australia, on 18 August for an overnight stop to top off with fuel and provisions. She got back underway on 19 August 1944 and headed for her patrol area in the waters of the Japanese-occupied Netherlands East Indies.

Just after midnight on 29 August 1943, Bilfish sighted what she thought was a large, unescorted Japanese tanker in the Sulu Sea, but the tanker's zigzag course enabled her to escape into the darkness before Billfish could reach a suitable attack position. While submerged at at 12:15 that afternoon, she sighted a Japanese ship exiting Balabac Strait at a range of which she took to be the tanker that had eluded her earlier. She surfaced and gave chase at . Finally in firing position at 22:17 at , she fired a spread of four torpedoes at the ship from her stern torpedo tubes. The torpedoes passed under the ship, which then turned and revealed herself to be a small warship rather than the expected deep-draft vessel for which Billfish had set the torpedoes′ depth setting. Billfish withdrew at full power and evaded the warship.

While in position at 06:21 on 8 September 1943, Billfish sighted the smoke of what turned out to be a convoy of five Japanese ships steaming in the South China Sea along the coast of Japanese-occupied French Indochina. She chased the convoy until late afternoon, when she closed to within torpedo range. At 16:38 in position she launched a spread of four torpedoes from her bow tubes, then went deep and rigged for depth charging. Her crew heard an explosion, but Japanese warships counterattacked, forcing Billfish to go as deep as while they dropped 15 depth charges between 16:42 and 17:10, inflicting only minor damage on Billfish. As a result, she was unable to assess the results of her attack. She claimed to have damaged one cargo ship, but postwar analysis revealed that her target, the 5,832-gross register ton Norway Maru, escaped damage.

At 08:25 hours on 25 September 1943, Billfish was at when she sighted a convoy of five Japanese ships escorted by a torpedo boat. The convoy altered course away from her at a range of at 09:43, preventing her from reaching an attack position. She surfaced at 12:00, reported her sighting, and began an "end around" on the convoy's right flank to get ahead of it. At 12:10, she sighted the submarine surfacing away and beginning an end around on the convoy's left flank. Meanwhile, the submarine had heard her contact report and engaged the convoy, and at 12:14 Billfish heard a loud explosion as Bowfin torpedoed and sank the 8,120-gross register ton passenger-cargo ship Kirishima Maru. Billfish saw Bowfin surface about to her north at 13:50. The convoy had scattered, so Billfish pursued the easternmost ship, and sighted two other ships at 14:00. She established radar contact on the targets at a range of as darkness fell, and at 19:12 was in a good position to begin an attack approach from a range of , but the ships altered course away. She again worked ahead of them, and at position fired a spread of five torpedoes from her bow tubes at 20:03. Her crew saw a bright flash and a water column rise from the stern of one Japanese ship, which stopped, began to settle, and opened gunfire as Billfish retired to a range of . She attempted another attack overnight, but did not achieve an attack position. Billfish claimed a torpedo hit and damage to one ship, but postwar analysis did not confirm this claim.

On 3 October 1943, Billfish made a southbound transit of Lombok Strait on the surface. She stopped at Exmouth Gulf on the coast of Western Australia to refuel on 7 October, and ended her patrol with her arrival at Fremantle, Australia, on 10 October 1943.

Second war patrol

After refit, Billfish put to sea again on 1 November 1943 to begin her second war patrol. After stopping at Exmouth Gulf on 4 November 1943 to top off with fuel, she made a submerged northbound transit of Lombok Strait on 9 November and headed through the Netherlands East Indies via the Makassar Strait and waters north of Borneo toward a patrol area in the South China Sea off the coast of French Indochina.

While she was in the Makassar Strait at at 09:20 on 11 November 1943, she sighted an approaching Japanese torpedo boat which passed her, apparently unaware of her presence. At 14:07, she sighted a destroyer or another torpedo boat and began an approach. She abandoned her approach at a range of at 14:50, but the vessel turned and headed toward her, so she submerged to and rigged for silent running and depth charging. The Japanese ship dropped six depth charges at 15:05. Billfish sustained considerable minor damage and descended to . Six more depth charges exploded at 16:40 with Billfish at , inflicting no additional damage. Soon thereafter, Billfish detected the arrival of a second Japanese ship, and the two ships made a combined attack with eight depth charges at 19:00. With all officers senior to him incapacitated by panic and no one manning the helm, the diving officer, Lieutenant Charles W. Rush, found himself the senior man still able to carry out his duties."Submariner Receives Navy Cross: Interview: Captain Charlie Rush, USN (Ret.)," Naval Institute Proceedings, June 2002 After 12 continuous hours at his station as diving officer, Rush turned over control of the dive to a junior officer and assumed command. Rush realized that Billfish′s damaged fuel tanks were leaking profusely and that the Japanese undoubtedly were tracking her by the oil slick she was leaving, so, with Billfish at , some below her test depth – according to Rush's award citation, although he claimed she was at , which was below her test depthmilitary times.com The Hall of Valor Project: Charles W. Rush Accessed 5 February 2023 – he reversed course so precisely that Billfish was able to proceed back down her previous track, using the floating oil slick as cover and defeating its usefulness to the Japanese as a trail. Meanwhile, Chief Electrician's Mate John D. Rendernick took action from his battle station and led emergency repairs, which included using a hydraulic jack to reposition the port main motor, which had been knocked off its foundation, and filling a leaking stern torpedo tube with grease. Some four hours after the Japanese attack finally ceased, Billfish surfaced under the cover of darkness at 00:25 on 12 November, recharged her batteries using the single operating generator, and completed repairs. For his actions, Rush was awarded the Navy Cross on 5 April 2002. Rendernick was awarded the Navy Silver Star posthumously, and on 17 August 2004 the Naval Submarine Training Center John D. Rendernick Damage Control Wet Trainer at Pearl Harbor, Hawaii, was named in his honor.

Billfish continued her patrol. While transiting Sibutu Passage, she slipped by a Japanese antisubmarine warfare ship without harm and entered the South China Sea on 16 November 1943.

From time to time during the patrol, Billfish again teamed up with Bowfin. In the predawn darkness of 28 November 1943, Billfish detected an escorted five-ship Japanese convoy and reported the find to Bowfin. In a surface attack on the convoy, Bowfin fired a spread of four torpedoes, all of which hit and quickly sank the 2,866-gross register ton tanker Tonan Maru. Only moments later, Bowfin fired two bow torpedoes, which struck another ship, leaving its bow awash. A third ship headed for Bowfin at high speed, firing its guns at her. One shell hit Bowfin, causing considerable damage, but Bowfin fired two torpedoes from her stern tubes which sent the 5,425-gross register ton passenger-cargo ship Sydney Maru to the bottom. Out of torpedoes, Bowfin headed for Australia a short time later. Meanwhile, Billfish got into position to fire four torpedoes from her stern tubes at one of the Japanese ships still afloat after Bowfin′s attack. Though Billfish soon heard explosions, she was unable to observe the results of the attack.

While heading through the Celebes Sea toward Australia on 5 December 1943, Billfish survived a Japanese attack of 15 depth charges. Unscathed, she reached Fremantle on 24 December 1943.

Third war patrol

After a refit, Billfish got underway on 19 January 1944 and headed back to the South China Sea for her third war patrol. She transited Sibutu Passage on the evening of 1 February 1944 and at around 23:30 opened fire with her gun on two Japanese "sea trucks, " a U.S. term for small Japanese cargo ships. The Japanese ships responded with erratic gunfire and scored a few hits on Billfish′s deck aft. Undamaged, Billfish set one of the ships afire and left the second listing dangerously.

On 13 February 1944, a comparatively small Japanese warship surprised Billfish on the surface and bracketed her with gunfire, forcing her to go deep. A depth-charge attack ensued but she sustained no damage. After a final brush with a Japanese convoy on 1 March 1944, she returned to Fremantle on 24 March 1944.

Fourth war patrol