Question 3906 Deck General

The correct answer is B) shallow water. Water may boil up around the stern of a vessel in a channel due to shallow water. When a vessel is operating in shallow water, the water flowing under the vessel can create turbulence and boiling around the stern as the water is displaced by the vessel's draft. This is a common phenomenon and is not caused by a cross current (A), slack water when upbound (C), or a head current (D). The shallow water beneath the vessel is the primary factor that leads to the boiling or agitated water around the stern in this scenario.