INDOOR OCEAN The Navy's Indoor Ocean -- the maneuvering and seakeeping basin, or MASK -- is 240-feet wide, 360-feet long and holds over twelve-million gallons of water. Its mission is to test ship designs and ocean wave patterns at the Naval Surface Warfare Center, Carderock Division, located in Maryland. SHARE: Download: Full Size (0.08 MB) Tags: Lead Photos Credit: VIRIN: 215021-I-RSX31-600.jpg Photo Gallery