(mahjong) a tile that one can safely discard, as it cannot become an opponent's advantage / (slang, by extension) a safe choice

(government, military, economics, diplomacy) security

sightseeing boat; tour boat; pleasure boat (ship)

a large warship using during the 16-17th century in Japan

steamship

a type of military boat used between the Warring States Period and the Edo Era

a spaceship (vehicle that flies through space, designed to fly with human onboard)

icebreaker (ship designed to break through ice)

cargo ship, freighter

patrol boat