Question 752 Rules of the Road

The correct answer is C) a sailing vessel underway. According to the Navigation Rules, both International and Inland, a sailing vessel underway displays a single green light at night. This is to indicate the vessel's port (left) side. The other options are incorrect because: A) A drifting vessel would not display any navigation lights. B) A small motorboat underway would display a combination of red and green sidelights, not just a single green light. D) A vessel at anchor would display an all-round white anchor light, not a single green light.