A law enforcement vessel patrolling a marine regatta may show either a flashing blue light or what other signaling device?

• A. A high intensity flashing white light (strobe)
• B. A continuous red beacon
• C. A green rotating beacon
• D. A visible flag

Answer: (A)

The essential idea is that vessels enforcing safety during events can use signaling devices that clearly mark their authority. A blue flashing light is the standard symbol of that authority, but if it isn’t used, a high‑intensity flashing white light (a strobe) serves the same purpose: it’s highly visible, quickly communicates that the vessel is asserting control, and helps mariners recognize and comply with instructions in a busy regatta environment.

The other options don’t convey authority in the same way. A continuous red beacon is not the recognized signal for enforcement; a green rotating beacon is generally used for other safety or service purposes and not for law enforcement signaling; a visible flag lacks the immediacy and reliability of a flashing light, especially in varying daylight and cluttered situations on the water.