In the two years preceding the United States's entry into World War II, "Searaven" operated in Philippine waters conducting training and maneuvers. At the outbreak of war between the United States and the Japanese Empire, the submarine was at the Cavite Navy Yard in Manila Bay. During her first two war patrols in December 1941 and the spring of 1942, she ran supplies to the American and Filipino troops besieged on the Bataan Peninsula and Corregidor Island. In a night action in the Molucca Strait on 3 February 1942, "Searaven" engaged a Japanese destroyer with Mark 14 torpedoes. Two official sources conflict, regarding the results of this engagement. If confirmed it would have been "Searaven"s first kill of the war.