BOTH INTERNATIONAL & INLAND At night, you see the display of lights shown in illustration D074RR below. These lights indicate which of the following?

Correct Answer: Option D — sailing vessel

Under COLREGS Rule 25(a) and (b), a sailing vessel underway exhibits sidelights and a stern light only, without any masthead lights. This specific combination differentiates it at night from power-driven vessels, fishing vessels, and vessels not under command.