Qualla: The Submarine That Hunted a U-Boat in the Java Sea

The Submarine That Hunted a U-Boat in the Java Sea: Introduction

Thu, 02 Apr 2026 00:00:00 GMT

Photo credit Public domain. On April 23, 1945, fifteen days before Germany's unconditional surrender, a Balao-class submarine named Besugo was patrolling the Java Sea when her crew spotted something that should not have been there: a submarine painted in Japanese colors. It was not Japanese. It was U-183, a German Type IXC/40 U-boat operating thousands of miles from the Atlantic, one of the Kriegsmarine's Monsun boats based out of occupied Penang. Besugo fired a torpedo. U-183 went down with all hands except one -- a badly wounded warrant officer named Wisniewski, whom the Americans pulled from the water. In that single engagement, USS Besugo became one of the very few American submarines to sink a German naval vessel during the entire war, and she did it in a theater where no one expected the two navies to meet.

Image: Public domain

The Submarine That Hunted a U-Boat in the Java Sea: Built for the Deep

Thu, 02 Apr 2026 00:00:00 GMT

Photo credit Public domain. Besugo's keel was laid down on May 27, 1943, at the Electric Boat Company yard in Groton, Connecticut -- the same shipyard that had been turning out submarines since the earliest days of American undersea warfare. She was launched on February 27, 1944, a Balao-class boat displaci...

Image: Public domain

The Submarine That Hunted a U-Boat in the Java Sea: Five Patrols Across Hostile Water

Thu, 02 Apr 2026 00:00:00 GMT

Photo credit Public domain. Between September 1944 and July 1945, Besugo completed five war patrols that took her through some of the most dangerous waters in the Pacific. Her first patrol sent her to the Bungo Channel, the strait leading to Japan's Seto Inland Sea, where she hunted alongside the submarines...

Image: Public domain

The Submarine That Hunted a U-Boat in the Java Sea: The Monsun Boat

Thu, 02 Apr 2026 00:00:00 GMT

Photo credit Public domain. U-183 had traveled a long road to reach the Java Sea. Commissioned in April 1942, she was one of the Kriegsmarine's Monsun Gruppe -- submarines dispatched to operate in the Indian Ocean from Japanese-held bases in Southeast Asia, primarily Penang in occupied Malaya. The Monsun bo...

Image: Public domain

The Submarine That Hunted a U-Boat in the Java Sea: Cold War Currents and a Venetian Name

Thu, 02 Apr 2026 00:00:00 GMT

Photo credit Public domain. The war's end did not retire Besugo. She served through the Korean War, earning a battle star, and continued Cold War operations with the U.S. Navy until 1958. Then came a second life no one could have predicted. On March 31, 1966, Besugo was decommissioned and loaned to Italy. T...

Image: Public domain

The Submarine That Hunted a U-Boat in the Java Sea: Where the Oceans Crossed

Thu, 02 Apr 2026 00:00:00 GMT

Photo credit Public domain. Besugo earned the Combat Action Ribbon, the Asiatic-Pacific Campaign Medal with four battle stars, and a string of other decorations. But her legacy is defined by that single torpedo on April 23, 1945. The Java Sea, where she sank U-183, sits at a geographic crossroads -- the wat...

Image: Public domain