潜望鏡
　　The point is not whether the officers used the periscope or not, but whether they were looking into the periscope with sufficient carefulness which seamanship dictates.　要点は、士官たちが潜望鏡を使ったか否かではなく、彼らが、航海術の 規定通りの充分な注意深さで潜望鏡を見つめていたか否かだ。
　　After they "thoroughly scanned the surface through the periscope," Greeneville conducted "emergency surfacing" and collided with the Ehime maru, a Japanese fisheries training boat for high school students.　彼らが 「潜望鏡を通して完全に海面を調べた」 あと で、グリーンヴィルは「緊急浮上」を実行し、日本の高校生のための漁業訓練船愛媛丸に衝突した。