海かい上じょう

noun, noun which may take the genitive case particle 'no'

on the sea; maritime; surface of the sea

Refers to the sea surface or to things happening on the sea, often in contrast with land or air. Common in compounds like 海上交通 (maritime traffic) and 海上自衛隊 (Maritime Self-Defense Force).

• 海かい上じょうは穏おだやかで、船ふねは順じゅん調ちょうに進すすんだ。

  The sea was calm and the ship sailed smoothly.

• 海かい上じょう保ほ安あん庁ちょうが救きゅう助じょに向むかった。

  The Japan Coast Guard headed to the rescue.