キャッチャーボート

noun

whale catcher; catcher boat

A vessel used in whaling to chase and harpoon whales, often working in conjunction with a factory ship.

from English catcher boat

• キャッチャーボートが鯨くじらを発はっ見けんし、母ぼ船せんに知しらせた。

  The catcher boat spotted a whale and notified the mother ship.