Harb. & Nav. Code, § 281

Whenever any vessel, whether a steam vessel or sailing vessel, proceeding in one direction, meets another vessel, whether a steam vessel or sailing vessel, proceeding in the opposite direction, so that if both were to continue their respective courses they would pass so near as to involve the risk of a collision, each shall give right rudder, so as to pass on the port side of each other. This rule applies to all steam vessels and all sailing vessels whether on the port or starboard tack, and whether close-hauled or not, except where the circumstances of the case are such as to render a departure from the rule necessary in order to avoid immediate danger. It is subject to a due regard to the dangers of navigation, and, as regards sailing vessels on the starboard tack close-hauled, it is subject also to the keeping of such sailing vessels under command.