Related Clues:

• Sub of WWII
• Naval convoy menace
• German war vessel
• Underwater weapon
• WWII torpedo launcher
• German submarine
• WWII enemy sub
• "Das Boot" setting
• WWII German sub
• Missile
• Lusitania's downfall
• ''Das Boot,'' for one
• Liner threat, once
• Depth charge target
• World War II sub