The sinking of USS Corvina

On the night of 16–17 November 1943, several hundred kilometres south of Truk atoll, the Japanese submarine I-176 fired three torpedoes at an American submarine that was charging its batteries on the surface in the moonlight. Two hit; the target blew up and went down with all hands. She was USS Corvina – the only American submarine sunk by a Japanese submarine in the entire war. Eighty-two men died. For many weeks the Americans did not know what had become of her; certainty came only from Japanese documents captured and analysed after the war.

A new boat on her first patrol

Corvina belonged to the Gato class – large ocean-going submarines that formed the backbone of the American submarine force in the Pacific. Her keel was laid on 21 September 1942 at the Electric Boat yard in Groton, Connecticut; she was launched on 9 May 1943 and commissioned on 6 August under Commander Roderick S. Rooney. After training in the Atlantic, Corvina left New London on 18 September and reached Pearl Harbor on 14 October.

On 4 November 1943 she set out on her first war patrol. Two days later she refuelled at Johnston Atoll, the last American outpost before the vast Japanese-held central Pacific. Her task was a difficult one: to patrol as close as possible to Truk, the great base of the Combined Fleet in the Carolines, and intercept Japanese warships that might sortie from there against the approaching American offensive in the Gilbert Islands. To this end Admiral Chester Nimitz, Commander-in-Chief of the Pacific Fleet, deployed several submarines around Truk and the Marshall Islands – they were to be the eyes and the first barrier against the Japanese fleet. Corvina reported in for the last time from Johnston; after that nothing more was heard from her.

The Japanese hunter

I-176 was an experienced boat. Built at the Kure naval arsenal, in October 1942 she torpedoed and badly damaged the American heavy cruiser USS Chester south of the Solomon Islands – at a time when Japanese submarines were enjoying their greatest successes in those waters, the most famous example being the sinking of the carrier USS Wasp by I-19 in September 1942. Later, like many Japanese submarines, I-176 was converted into a transport: her deck gun was removed and she carried food and ammunition to the cut-off garrisons on Guadalcanal and New Guinea. In March 1943, off Lae, American B-25 bombers strafed her while she was unloading, wounding her commander.

At the beginning of November 1943 I-176 was operating from Rabaul, which for a month had been under heavy Allied air raids. On 2 November, sent to rescue survivors from the cruiser Sendai, sunk in the night-time Battle of Empress Augusta Bay off Bougainville, she was depth-charged by an American Catalina flying boat; the damage to her hull forced her commander, Lieutenant Commander Kōzaburō Yamaguchi, to abandon the mission. After makeshift repairs at Rabaul, the boat left for Truk on 13 November, from where she was to sail to Japan for a refit.

A duel in the moonlight

American radio intelligence read the Japanese signals giving I-176’s route. On 16 November an Ultra message went out to three American submarines in the Truk area – Corvina, Drum and Blackfish – ordering them to intercept the Japanese boat. As events showed, the hunter became the hunted.

The course of the engagement is known only from Japanese records, since no one survived on the American side. According to I-176’s log, on the evening of 16 November, some 300 nautical miles (about 550 km) south of Truk, Japanese lookouts spotted a dark shape about 8 km away in bright moonlight. Within a few minutes they identified it as a submarine, most likely charging its batteries on the surface. Yamaguchi dived, switched to silent running and began his approach. He changed his plan several times – he even considered surfacing and attacking with gunfire – because at one point the American boat turned towards him. Finally, after midnight Tokyo time, and so on 17 November by that reckoning, he fired three torpedoes from his bow tubes. About 25 seconds later two powerful explosions were heard aboard I-176, shaking the Japanese boat herself. When she surfaced at the scene of the attack half an hour later, her crew saw only an oil slick and debris. According to the Japanese record, the submarine was sunk at 5°50′ N, 151°10′ E.

The official American history of US Navy ships (the Dictionary of American Naval Fighting Ships) gives the date as 16 November, and this is usually taken as the day of the sinking. The Japanese sighted Corvina while it was still 16 November, but the torpedoes were fired after midnight, so strictly speaking she sank on the night of 16–17 November. Although the sinking is often described in shorthand as having taken place “near Truk”, the spot lay several hundred kilometres from the base itself, on its approaches from the direction of Rabaul.

I-176 reached Truk on 18 November. The crew were welcomed as heroes, and the commander of the Sixth Fleet (the submarine force) gave a banquet in their honour. Two days later the boat sailed for Kure for her refit. The Japanese reported the sinking of an American submarine, but on the American side there was silence: Corvina did not answer radio calls and did not return from patrol. On 23 December 1943 she was declared overdue and presumed lost, and on 14 March 1944 the Navy announced her loss. Only a post-war comparison of Japanese documents made it possible to attribute her sinking to I-176.

An exception in the submarine war

The sinking of Corvina was an exceptional event. In 1941 the Japanese navy had one of the strongest submarine fleets in the world, with large, fast boats and excellent oxygen-powered torpedoes, but it used them chiefly against warships and, from 1943, increasingly to supply cut-off islands. Submarine-versus-submarine encounters were rare in this war and usually ended in success for the American side, which thanks to radar and radio intelligence more often saw the enemy first. In November 1943 the roles were reversed: the Americans knew about I-176 from decrypted signals, but it was the Japanese boat that spotted its enemy first.

Meanwhile the American submarine war was reaching a turning point. For almost two years submarine commanders had been plagued by the defects of the standard Mark 14 torpedo: it ran deeper than set, its magnetic exploder detonated prematurely, and its contact exploder often failed on a hit at right angles. Thanks to the persistence of Rear Admiral Charles Lockwood, commander of the Pacific Fleet’s submarines, who ordered his own tests in defiance of the Bureau of Ordnance, the faults had essentially been eliminated by September 1943. At the same time, from early 1943 the Americans were reading the Japanese merchant shipping code and could send their submarines straight at convoys. The effect showed in the figures: according to the post-war Joint Army–Navy Assessment Committee (JANAC), American submarines sank about 180 Japanese merchant ships (some 725,000 tons) in 1942, and about 300 (some 1.3–1.5 million tons, depending on the tally) in 1943. For Japan, which could not build new ships fast enough, this was the beginning of a shipping catastrophe.

Place in the war

The loss of Corvina was a reminder that the submarine war exacted a price from the winning side too. Over the whole war the US Navy lost 52 submarines – the great majority of them in the Pacific – and about 3,500 sailors, making submarine service the most dangerous in the American navy. That same month, on 19 November, another boat deployed to cover the Gilberts offensive was lost near Truk – USS Sculpin, sunk by a Japanese destroyer. A few days later the Americans landed on Tarawa and Makin, opening the offensive in the central Pacific that Corvina had been meant to guard.

I-176 did not long outlive her victim. After her refit in Japan she returned to transport duties, and on 16 May 1944 the American destroyers Franks, Haggard and Johnston tracked her down and sank her with depth charges off Buka Island in the Solomons. Her entire crew was lost. According to the official US Navy history, Corvina remained the only American submarine sunk by an enemy submarine.