This is the 4794th most frequent Japanese word.
水中
"Underwater" or "in water."
Used to indicate the location where fish are (underwater).
水中に魚がいます。
There are fish in the water.
Refers to the activity taking place underwater.
水中で泳ぐのは楽しいです。
Swimming underwater is enjoyable.
Describes the specific function of a camera (taking photos underwater).