INLAND ONLY A vessel engaged in public safety activities may display an alternately flashing red and yellow light. This special light may be used by a vessel engaged in which of the following?

Correct Answer: Option D — patrolling a regatta

33 CFR 83.35(j) (Rule 35) allows vessels engaged in public safety activities, such as patrolling a regatta or marine event, to display an alternately flashing red and yellow light. This specific light helps identify the vessel's authority and function to other mariners in the vicinity.