Final answer:
A sailing vessel is required to keep her course and speed when being overtaken by another vessel, as per the International Regulations for Preventing Collisions at Sea (COLREGs).
Step-by-step explanation:
A sailing vessel must keep her course and speed when being overtaken by another vessel. This is in accordance with maritime navigation rules, specifically the International Regulations for Preventing Collisions at Sea (COLREGs).
Under these rules, if a vessel is overtaking another, the vessel being overtaken should maintain her course and speed to allow for predictable maneuvers by the overtaking vessel. This is critical for preventing accidents and ensuring the safety of vessels on the water.
Conversely, when a sailing vessel is to leeward of another sailing vessel which is on a convergent course, the vessel which is to leeward must keep clear under Rule 12 of the COLREGs. This is because the vessel to windward has less maneuverability due to the wind position.