midget submarine

midget combat unit

midget sub

midget truck

single-digit midget

anti-submarine search

anti-submarine ship

anti-submarine warfare (ASW)

anti-submarine warfare cruiser

anti-submarine warfare officer

anti-submarine warfare patrol aircraft

anti-submarine warfare platform

anti-submarine warfare sensor data

anti-submarine warfare ship

attack submarine (SSN)

ballistic missile submarine (SSBN)

coastal submarine

disabled submarine (DISSUB)

distressed submarine (DISSUB)

distressed submarine personnel

guidance submarine

guided missile submarine

HM Submarine

hunter-killer submarine

killer submarine

life guard submarine

mini-submarine

nuclear propulsion submarine

nuclear submarine

nuclear-powered ballistic missile submarine (SSBN)

nuclear-powered submarine

Ohio-class submarine

open submarine warfare