INLAND ONLY While underway during the day you sight a small motorboat showing a flashing blue light. What does the blue light indicate?

Correct Answer: Option C — law enforcement boat

33 CFR 83.34(h) mandates that a flashing blue light is used exclusively to identify law enforcement vessels. Regardless of the vessel's size or the time of day, the presence of this light indicates an official law enforcement boat, requiring other mariners to comply with any instructions or signals given.