Port and starboard are nautical terms which refer to the left and right sides, respectively, of a ship as perceived by a person on board facing the bow (front). At night, the port side of a vessel is indicated with a red navigation light and the starboard side with a green one. The starboard side of most naval vessels the world over is designated the “senior” side. The officers’ gangway or sea ladder is shipped on this side and this side of the quarterdeck is reserved for the captain.