Complete levels 1 to 4

Complete levels 5 to 8

Complete levels 9 to 12

Complete levels 13 to 16

Complete levels 17 to 20

Complete levels 21 to 24

Complete levels 25 to 28

Complete levels 29 to 32

Complete levels 33 to 36

Complete levels 37 to 40

Complete levels 41 to 44

Complete levels 45 to 48 and finish the game

Sink a Sub

Sink a Frigate

Sink a Destroyer

Sink a Battle ship

Use every item at least once in a single session

Complete a level without using any special weapons

Sink a Carrier

Sink a Cruiser