Lost at Sea
On February 11, 1943, Grampus, in company with Grayback (SS-208), departed Brisbane to patrol the Blackett Strait area. ... Grayback reported sighting Grampus in her assigned area on 4 March. Nothing further was seen or heard of Grampus and her crew of 71 following that date. ... Analysis of Japanese records after the war indicates that IJN destroyers Minegumo and Murakomo attacked and sank a submarine in that area on March 5, possibly by gunfire. Amplifying information is unavailable, since both destroyers were sunk on March 7, with the loss of their logs and battle reports.