Which effect does speed through the water have on a vessel which is underway in shallow water?

Correct Answer: Option A — An increase in speed results in the stern sucking down lower than the bow.

In shallow water, the Bernoulli principle causes a pressure drop under the hull as water velocity increases. This creates 'squat,' where the vessel sinks deeper into the water. As speed increases, the stern experiences a greater pressure drop than the bow, causing the vessel to trim by the stern.