USS Sealion Sinks Japanese Battleship Kongō

Context

By late 1944, the Imperial Japanese Navy faced mounting losses across the Pacific as Allied forces advanced toward the Philippines and prepared operations against Formosa and the Japanese home islands. Following the decisive Battle of Leyte Gulf in October, surviving Japanese capital ships were often committed to high-risk transits between bases to support defensive operations or return for repairs. American submarines, operating from advanced bases in the central and western Pacific, conducted aggressive patrols in chokepoints such as the Formosa Strait to interdict these movements and further erode Japanese surface strength.

What Happened

On the night of November 20–21, USS Sealion (SS-315), a Balao-class submarine under Lieutenant Commander Eli T. Reich, patrolled the northern Formosa Strait. Radar contact at approximately 00:20 revealed a large Japanese formation steaming northward at about 16 knots without zigzagging; it comprised the battleships Yamato, Nagato, and Kongō, the light cruiser Yahagi, and six destroyers. Sealion maneuvered ahead of the column and, around 02:56, fired six torpedoes at the second ship, Kongō. Three struck home, flooding boiler rooms and causing a port list. A follow-up salvo intended for another battleship instead hit and detonated the destroyer Urakaze, which sank rapidly with the loss of all hands.

Aftermath

Sealion continued pursuit of the damaged Kongō, firing additional torpedoes that contributed to progressive flooding. Hours later, a catastrophic explosion—likely from a forward magazine—sent the battleship to the bottom in the Formosa Strait northwest of Keelung. The task force scattered, and Kongō was formally stricken from the Japanese naval register in January 1945. The action removed one of the Imperial Navy’s few remaining fast battleships and underscored the persistent threat posed by U.S. submarines to Japanese surface units even in the war’s final phase.

Legacy

Kongō’s loss stood as the sole instance of a Japanese battleship sunk by submarine attack in World War II and highlighted the decisive contribution of American undersea forces to the isolation of Japanese naval power. Historians note that such interdictions accelerated the erosion of the Imperial Navy’s ability to contest Allied advances in 1945, while Sealion’s success under Reich earned him a third Navy Cross and cemented the boat’s place in submarine lore.