10 January 1944: 185 miles NW of Torishima, Ogasawara (Bonins). At about 0600, in typhoon weather conditions, Yamabiko Maru is torpedoed by LtCdr David L. Whelchel's USS Steelhead (SS-280). She is hit in the engine room by one of four torpedoes Whelchel fires in a night surface radar attack made at 31-28N, 137-44E. Yamabiko Maru is taken in tow by cargo ship Yamakuni Maru. The convoy's speed slows to 8 knots.