潜せん水すい艇てい

noun

submersible; small submarine

Refers to a small underwater vessel, often for research, exploration, or military use, distinct from larger military submarines (潜水艦).

• 深しん海かい探たん査さ用ようの潜せん水すい艇ていが開かい発はつされた。

  A submersible for deep-sea exploration was developed.

• その潜せん水すい艇ていは３人にん乗のりだ。

  That submersible carries three people.