noun, noun which may take the genitive case particle 'no'
underwater; in the water
Refers to being or occurring beneath the surface of water. Commonly used as a noun or with の to modify another noun.
水中カメラで魚の写真を撮った。
I took pictures of fish with an underwater camera.
彼は長い間水中に潜っていられる
He can stay underwater for a long time.