A power-driven vessel has on her port side a sailing vessel which is on a collision course. The power-driven vessel is to ______________.

In this scenario, the power-driven vessel is required to keep clear of the sailing vessel. According to maritime navigation rules, particularly the "Rules of the Road," power-driven vessels generally have a responsibility to yield the right of way to sailing vessels under sail when they are on a collision course.

Keeping clear means that the power-driven vessel needs to take action to avoid the potential collision, whether that involves changing course or speed to ensure safe navigation. The rationale for this is based on the principle that a sailing vessel typically has limited maneuverability compared to a powered vessel, which can make immediate course adjustments easier.

By adhering to this rule and keeping clear, the power-driven vessel enhances safety at sea and reduces the risk of accidents, ensuring that both vessels can navigate their respective paths without coming into conflict.