The pack arrived in the East China Sea in October 1943. It proved unable to solve the problems of communication and risk of fratricide, and made only one joint attack on a single convoy, but was credited at the time with sinking five Japanese ships for 88,000 tons and damaging eight others for 63,000 tons between them. (This was reduced to three sunk for 23,500 tons by JANAC postwar.) Momsen also received the Legion of Merit for work on the Navy's wolfpacks from February 1943 to June 1944. Momsen earned a Navy Cross for his efforts.