 Between March 2000 to July 2005 Kasatonov was captain of the battlecruiser "Pyotr Velikiy".It was during the Northern Fleet's annual exercises in the Barents Sea in August 2000 that the Oscar II-class submarine K-141 "Kursk" suffered a fatal accident and sank.The exercises, which began on 11 August, were the largest Russian naval exercises since the dissolution of the Soviet Union in 1991.