LIGHTS AND SHAPES Rules for lights must be complied with in all weather, from sunset to sunrise, as specified by both International and Inland Rules of the Road. Navigational lights and dayshapes of another vessel convey information such as clues to the type and size of vessel, its heading in relation to your vessel, type of operation in which it may be engaged, and other data that is helpful in determining right of way and preventing a collision. Various navigational light and dayshape displays prescribed by the rules are discussed in the following topics. Running Lights When the rules refer to a power-driven vessel, they mean one propelled by any kind of machinery, as distinct from a sailing ship under sail. A vessel under way means a ship not at anchor, not made fast to the shore, or not aground. The ship does not actually have to be making headway. Both rules state that the rules for lights must be complied with in all weather from sunset to sunrise, and should also be exhibited from sunrise to sunset in restricted visibility. These lights may be exhibited in all other circumstances when it is deemed necessary. Ships usually are darkened during wartime conditions; but even then, lights are kept ready for immediate display. MASTHEAD LIGHT.—You are aware that a power-driven vessel underway carries a white light (masthead light) placed over the fore and aft centerline of the vessel, showing an unbroken light over an arc of the horizon of 225° and so fixed as to show the light from right ahead to 22.5° abaft the beam on either side of the vessel. The light at the fore masthead, or some other elevated point forward, is between 20 and 40 feet above the deck. This light must be visible from 2 to 6 miles, depending on the length of the vessel. You know, too, that under both rules, a power-driven vessel over 50 meters in length shows another white light aft, at least 15 feet higher than the fore masthead light. The horizontal distance between these lights should not be less than one-half the length of the vessel but need not be more than 100 meters. The after light, called the aft masthead light, is mandatory under both rules except for vessels less than 50 meters in length. A power-driven vessel less than 12 meters may show an all-round white light in lieu of the masthead light. SIDELIGHTS.—Sidelights mean a green light on the starboard side and a red light on the port side, each showing an unbroken light over an arc of the horizon of 112.5° and so fixed as to show the light from right ahead to 22.5° abaft the beam on its respective side. In a vessel of less than 20 meters, the sidelights may be combined in one lantern carried on the fore and aft centerline of the vessel. Side lights must be visible from 1 to 3 miles, depending on the size of the vessel. A sailing vessel or a ship being towed displays side lights and a stern light only—never masthead lights. A vessel under oars or a sailing vessel of less than 7 meters in length need carry only a lantern showing a white light, which it must exhibit in time to prevent collision. If practicable, a sailing vessel of less than 7 meters must exhibit the lights prescribed for a sailing vessel under way. STERNLIGHT. —A white light placed as nearly as practicable at the stern, showing an unbroken light over an arc of the horizon of 135° and so fixed as to show the light 67.5° from right aft on each side of the vessel. TOWING LIGHT.—The towing light is a yellow light having the same characteristics as a sternlight. Lights, Pilot Vessels An OOD or conning officer often is most anxious to sight the pilot boat and signal it alongside without being forced to lie to when conditions may be setting the ship toward a lee shore. Signalmen should recognize a pilot vessel the instant it is sighted. Pilot vessels, when engaged on their stations on pilotage duty, should not show the lights required for other vessels. A pilot vessel should exhibit at or near the masthead two all-round lights in a vertical line, the upper being white and the lower red, and when under way (fig. 9-22), in addition, sidelights and a sternlight. When at anchor, in addition to those lights previously described, the pilot vessel should show the anchor light, lights, or shape prescribed for anchored vessels. The daytime display for a pilot vessel is the display of the HOTEL flag. Pilot vessels, when not engaged on pilotage duty, should exhibit the lights or shapes prescribed for similar vessels of their length. Vessel at Anchor A vessel at anchor (fig. 9-23) should show, where it can best be seen, an all-round white light or one ball in the forepart of the vessel, and, at or near the stern, 9-22