reef

礁、暗礁、礁石

The ship struck a reef and began taking on water.

那艘船撞上暗礁，开始进水。

珊瑚礁

Warmer oceans are bleaching coral reefs around the world.

海水变暖正让世界各地的珊瑚礁白化。

缩帆部航海

He tied in a reef to reduce the sail area.

他系上缩帆部以减少帆面面积。

缩帆、卷帆航海

We reefed the mainsail as the wind picked up.

风势转强时，我们把主帆缩了起来。