水底船的設計最早在1500年代就已經開始了。到了19世紀，第一艘可用的潛艇開始成形。在內戰期間，南方聯盟建造了洪雷浩（H. L. Hunley）潛艇，在1864年時，擊沈了聯邦軍隊船艦修薩透尼克號（U.S.S. Housatonic）。但是一直要到第一次世界大戰期間，真正發揮作用的潛水艇才出現。你有沒有坐過潛水艇呢？問問你的家人他們有沒有這樣的經驗，感覺如何。

Designs for underwater boats date back to the 1500s. In the 19th century, the first useful submarines began to appear. During the Civil War, the Confederates built the H.L. Hunley, a submarine that sank a Union ship, the U.S.S. Housatonic, in 1864. But it wasn't until World War I that the first truly practical submarines emerged. Have you ever been on a submarine? Ask your family if they have and what it's like.