Aces of the Deep is a World War II submarine simulator game developed by Dynamix for MS-DOS in 1994. The game was re-released by Sierra On-Line for Windows in 1995 as Command: Aces of the Deep. Aces of the Deep was the last installment of Dynamix's Aces series, which included the flight simulators Red Baron, Aces of the Pacific, and Aces Over Europe. However, unlike its predecessors, Aces of the Deep simulates a Kriegsmarine U-boat during World War II.