INLAND ONLY You sight a vessel displaying an alternating red and yellow light. What does this light indicate?

Correct Answer: Option A — a vessel engaged in public safety activities

33 CFR 83.34(h) defines the alternately flashing red and yellow light as the signal for vessels engaged in public safety activities. This light serves as a visual indicator to other mariners that the vessel is performing an official, safety-related function, requiring appropriate caution and awareness from nearby traffic.