艦艇[kantei] military vessel
救命艇[kyuumeitei] lifeboat
魚雷艇[gyoraitei] torpedo boat
競艇[kyoutei] boat race
舟艇[shuutei] boat

巡視艇[junshitei] patrol boat
上陸用舟艇[jourikuyoushuutei] landing craft
掃海艇[soukaitei] minesweeper
漕艇[soutei] rowing
艇庫[teiko] boat-house

一首[isshu] tanka
鎌首[kamakubi] sickle-shaped neck (e.g. snake, praying mantis)
丸首[marukubi] round-necked (T-shirt)
偽首[nisekubi] falsified severed head
カリ首[karikubi] (something resembling a) goose's neck

がん首[gankubi] head of a pipe, incl. the bowl and stem attachment
機首[kishu] nose (of plane)
襟首[erikubi] nape of neck
元首[genshu] ruler
絞首刑[koushukei] death by hanging