機器
underwater
explosion
aggression
ammunition
army
boat
bomb
danger
defense
destroy
device
discharge
dive
equipment
exploding
explosive
fast
fire
forces
guard
implosion
industry
machinery
marine
metal
military
mine
missile
naval
navy
ocean
power
propeller
rocket
shell
ship
steel
strike
submarine
submerged
technology
tool
torpedo
war
warfare
warhead
weapon
ww2