We crossed the bay on a hydrofoil, which took half the time of a regular ferry.

hydrofoil 是由前缀 hydro-（表示“水”）和 foil（“箔、叶片”）组成的复合词。hydrofoil 指的是一种船体下方装有水翼的船只，当船速提高时，水翼产生升力使船体抬离水面，从而减少阻力提高速度。