A sound made by tapping on the hull of a shop will be reflected from the sea bottom, and depth of the sea at that point can be calculated.

在船体外壳上敲打发出的声音会从海底反射。通过测量敲打与接受回声的间隔时间，这一点的海底深度就可计算出来。

youdao

Model tests for this hull lines are conducted at different water depth in towing tank, and the effect of shallow water on craft performance is investigated.

针对该型线又进行了不同水深的阻力模型拖曳试验，并根据试验结果讨论了高速艇的浅水效应。

youdao

The captain proceeded in the fjords at very slow speed, barely moving forward, by lowering an anchor from the bow to a depth greater than the hull of the ship.

FORBES: It's Not Reality But Perception That Counts