USS Trigger (SS-237) was a submarine, the first ship of the United States Navy to be named for the triggerfish.
Construction Triggers keel was laid down on 1 February 1941 at Mare Island, California, by the Mare Island Navy Yard. She was launched on 22 October 1941, sponsored by Mrs. Walter N. Vernou, and commissioned on 30 January 1942.
Battle of Midway The submarine sailed for Hawaii on 22 May and reached Pearl Harbor the following week. She sortied for Midway Island with Task Group 7.2 (TG 7.2) on 29 May in anticipation of a Japanese attack on that island. Her station during the ensuing Battle of Midway was northeast of Midway, but her usefulness was curtailed when she ran aground. She freed from her grounding and returned to Pearl Harbor on 9 June.
First patrol: June–August 1942 On 26 June, Trigger got underway for the Aleutian Islands to patrol an area west of Cape Wrangell, Attu Island. She encountered six destroyers, three freighters and a patrol boat, attacking none, before calling at Dutch Harbor on 8 August en route back to Hawaii.
Second patrol: September–November 1942 Roy S. Benson assumed command before Trigger began her second war patrol, conducted from 23 September to 8 November in "Empire Waters" (the seas immediately surrounding Japan). In the early morning hours of 5 October, the submarine sighted smoke on the horizon and headed for it. A vessel soon appeared, coming toward the submarine. As the target approached, the submarine identified it as a small ship. Trigger then surfaced and manned her machine guns. As the target neared, however, the submarine learned that the Japanese ship was larger than initially thought. Enemy shells soon began exploding close to Trigger, and the 4,000 ton ship turned and accelerated in an attempt to ram the submarine. Trigger barely avoided a collision as she submerged for an attack; she launched two torpedoes and heard one hit. She then surfaced and gave chase, only to have the target again open fire. The submarine missed with three more torpedoes and then discontinued the pursuit.
Before dawn on the morning of 17 October, Trigger made a surface attack on a freighter off the Bungo Suido. She fired two spreads of torpedoes which sank Holland Maru with her guns still firing. That night, a destroyer came out of Bungo Suido and dropped a string of depth charges near the submarine. Trigger launched three torpedoes "down the throat" at the onrushing destroyer and, one minute later, observed an explosion so powerful it threw enough flame and water into the air to obscure the target. When the air cleared, the enemy ship was still intact, suggesting Triggers first torpedo may have exploded prematurely, detonating the next two by its turbulence. The submarine fired one more torpedo as the enemy disappeared, but failed to score a hit.
Near midnight of 20 October, Trigger fired a spread of four torpedoes from very close range, , in a surface attack on a 10,000-ton tanker. Two torpedoes hit the enemy ship as it turned in an attempt to ram. The submarine went to to evade a counterattack, and heard a heavy explosion as either gasoline, magazines, or boilers blew up. Trigger then came up to periscope level but found nothing in sight. (This sinking was not confirmed by JANAC postwar.) Four days later, Trigger attacked a large enemy tanker in ballast. A spread of three torpedoes produced three observed hits, one near the target's stern. The screws of the enemy ship stopped, and she began emitting heavy white smoke aft, but she soon got underway again. Trigger fired her last torpedo at the ship as it was moving off and missed. That night, she surfaced and began her homeward voyage.
Third patrol: December 1942–January 1943
From 3 December 1942 to 22 January 1943, the submarine conducted a combined minelaying and offensive patrol, again in waters surrounding the Japanese home islands. On 20 December, she began planting a minefield off Inubo Saki, Honshū. Trigger planted the northern half of the field and was working on the southern part when a cargo ship passed her, heading into the newly-laid mines. Five minutes later, a violent explosion rocked the freighter which sank while an escort circled her. The submarine later heard another explosion from the direction of the minefield and, when she surfaced the next day, found the field was covered by smoke.
On 22 December, Trigger sighted a ship approaching from Uraga and made a surface attack. A spread of three torpedoes produced one hit forward of the bridge, and the target started to settle by the bow. The submarine fired one more torpedo into the ship and, when last seen, Teifuku Maru was awash forward with her screws nearly out of the water. On 31 December 1942, she attacked a cargo ship loaded with planes. Trigger fired three torpedoes from extremely close range , and watched two hit. The target began to list to starboard and was down by the bow. Sound reported a heavy secondary explosion. The submarine came up to periscope level and saw the freighter with her stern high out of the water and a destroyer approaching. Trigger went deep and when she next came up for a look, there was nothing to be seen. (The sinking was not confirmed by JANAC postwar.)
On 10 January 1943, a Japanese destroyer approached Trigger, and the submarine fired three torpedoes from . One hit under the well deck and folded the destroyer's forecastle up at a 45° angle, and another hit the target's stern. Soon, the destroyer sank on an even keel.
Fourth patrol: February–April 1943 Trigger stood out of Midway on 13 February to patrol off the Palau Islands. Two weeks later, she launched four torpedoes at a freighter, but the target managed to steer between them. Heavy air cover prevented a second attack. On 4 March, the submarine attacked a freighter in a rain squall, but all three of her torpedoes missed. On 15 March, Trigger sighted a convoy steaming in two columns. There were two freighters in the right hand column and three in the left, with an escort on the outboard bow of each column. Trigger worked her way between the two columns and launched three torpedoes at each of the leading ships. She hit the lead freighter in the left hand column twice but missed her target on the right because it unexpectedly changed course. Trigger then fired three more torpedoes at the right lead ship at just and observed two hits before the escorts forced her to go deep. When she surfaced again, there was nothing to be seen. Trigger was later officially credited with having sunk Momoha Maru, a 3,103-ton cargo ship.
That night, the submarine fired six torpedoes at a ship that was being towed by a smaller freighter. Five of the torpedoes missed, and the sixth made a circular run and passed over the submarine's engine room. A shaken crew broke off the attack.
On 20 March, the submarine launched three torpedoes at the lead ship in a convoy of four cargo ships. One hit caused the target to list 10° to port and stop, but it soon got underway and rejoined the convoy. Trigger terminated the patrol at the Submarine Base, Pearl Harbor, on 6 April.
Fifth patrol: April–June 1943 Between 30 April and 22 June, the submarine made a patrol which returned her to Empire waters. Directed by an Ultra from Pearl Harbor, Trigger lay athwart the projected track of Admiral Koga's task force returning from Truk. Koga's force came in sight the morning of 22 May, but zigged away, out of range, "a bitter disappointment".Blair, Silent Victory, p.428 On 28 May, Trigger contacted two freighters off Iro Saki and fired three torpedoes at the larger. One hit aft. When last seen, the ship was down by the stern. The next day, the submarine fired a spread of three torpedoes at a small cargo ship. Two missed and the third exploded prematurely. She then fired a fourth torpedo, which apparently hit but failed to explode.
On 1 June, the submarine was searching for Japanese shipping off Sagami Nada when she sighted two columns of smoke. She closed the range toward a firing position, made out two cargo ships, and fired a spread of three torpedoes at each target. Hit in her stern, the lead ship, Noborikawa Maru, sank immediately. The second ship saw the torpedo wakes, turned and passed between them. Trigger then fired a torpedo at the oncoming ship; if the torpedo reached the target, it failed to explode.
Again alerted by Ultra, on 10 June (her last day on station), Trigger sighted an aircraft carrier protected by two destroyers. She closed and fired six torpedoes from only . Although as she went deep the submarine heard four explosions, postwar accounting showed two of the torpedoes missed ahead and one failed to explode. The escorts kept Trigger down for several hours.Blair, Silent Victory, p.430 The damaged limped into Tokyo Bay and was out of action for almost a year. Admiral Lockwood (COMSUBPAC), who knew Hiyōs fate, was furious. Had the torpedoes functioned correctly, Benson would have sunk her. The next day, Trigger began her return voyage to Pearl Harbor; just after her triumphant return, the Mark 14 torpedo's defective Mark 6 exploder was ordered deactivated.
Sixth patrol: September 1943 On 1 September, after a yard overhaul, Trigger (now in the charge of Commander Robert "Dusty" Dornin) was ready to begin her sixth war patrol. The patrol took her into the East China Sea, off the China coast, north of Formosa. On 17 September, she made two hits on a Japanese freighter, one aft and one on the bow, but both torpedoes proved to be duds. The next day, she again contacted the same ship and launched four torpedoes at her. One struck Yowa Maru, and the 6,435-ton cargo ship slid beneath the waves.
21 September was Triggers best day. She was patrolling some north of the Hoka Sho light when she sighted a convoy of three tankers and three freighters protected by Japanese planes. The submarine attacked the tankers first, firing three torpedoes at the leader and three at the second. One hit aft was seen on the lead tanker, and flames shot over into the air. The target's crew, dressed in whites, could be seen running forward to escape the fire. One torpedo hit the second tanker amidships, and it broke in half beneath the stack and sank immediately. Trigger turned and fired three stern tubes at the third tanker. This target swung toward the submarine, and all three torpedoes missed. Trigger then fired another torpedo which hit that ship's starboard side. When the submarine went deep, Dornin slipped and fell into the periscope well as the quartermaster was lowering it. He supported himself on his elbows, and the quartermaster heard his shouts in time to prevent a serious accident. Sonar reported two more explosions before the submarine came back up to periscope depth to resume the attack. Trigger fired two bow torpedoes at the third freighter in the column and scored two hits on the target which went down by the bow. The submarine then made two more attacks on the freighter, but all of her torpedoes either missed or were duds. During the three and one-half hours of action, Trigger sank two tankers, Shiriya and Shoyo Maru, and a freighter, Argun Maru, for a total of 20,660 tons of enemy shipping. The submarine returned to Midway on 30 September to be refitted and rearmed.
Seventh patrol: October–December 1943 The East China Sea and Yellow Sea were Triggers objective for her seventh patrol. She stood out of Midway on 22 October and proceeded to her patrol area. At 22:00 on 1 November, she sighted a convoy that was steaming in two columns. When a ship in the nearer column overlapped one in the more distant group, Trigger fired a spread of three torpedoes at them. One torpedo struck the nearer freighter in the bow and one hit the farther ship amidships. The submarine saw the nearer ship go down by the bow, before she herself was forced to go deep where she was severely depth-charged by two escorts.