Due to standard procedures the U-168 had alerted local Japanese units to the details of its departure and arrival, intended course and speed. This was decrypted and included in a FRUMEL report on October 5th, 1944. In response, the Zwaardvisch was ordered to intercept.
Action
KapitänleutnantHelmuth Pich commanded the boat during the time of her sinking. The submarine was steaming east to Soerabaja from Batavia where she was to rendezvous with and. From there, the wolfpack would operate against the western coast of Australia, but before meeting the other U-boats, U-168 was discovered on the surface by the T-class off the coast of Java in the Java Sea. Lieutenant Commander immediately changed course into the direction of the sub and ordered his crew to battle stations. At 06:53, 11 minutes after sighting the Germans, Zwaardvisch released six torpedoes from away on a 95° track. A few seconds later, an explosion was heard by the Dutch commander so he raised his periscope and observed as the enemy craft began to sink. Goossen also saw several officers and crewmen escaping from the conning tower hatch and they were captured. The torpedo hit U-168s bow and it quickly sank in of water off Java's northern coast at position. Twenty-three men were killed and 27 became prisoners; because space aboard Zwaardvisch was limited, however, 22 of the detainees were transferred to a fishing boat and allowed to go free. They eventually made it to the shores of Java. The prisoners included Kapitänluetnant Pich, three other officers and one wounded rating. Pich later informed the Dutch commander that his submarine was hit three times though only one torpedo exploded. An Australian Navy account gives a description of two torpedoes hitting the U-168 with one failing to detonate and the other exploding in the forward torpedo room. U-168 is not believed to have made any defensive maneuvers in the action, thus the Germans were sunk likely without realizing they were under attack until the torpedoes hit. The Kriegsmarine was convinced that the sinking of U-168 was the result of "loose talk" due to the crew who brought their Indonesian girlfriends aboard for a goodbye party. They also assumed that the exact position of U-168 was discovered by the Allies long before the engagement, though Dutch reports suggest that they encountered the Germans simply by chance.
