lights. Supply switches for these lights are located on the signal and anchor light supply and control panel (in the pilothouse). The switches are individual on-off rotary  snap  switches. The aircraft warning lights (red) for ships are 32-point (360°) lights installed at the truck of each mast that extends more than 25 feet above the highest point in the superstructure. Two aircraft warning lights are installed if the light cannot be located so that it is visible from  any  location  throughout  360°  of  azimuth.  The fixtures are spraytight and are equipped with multiple sockets  provided  with  15-watt,  1-filament  lamps. Blinker lights for ships are located on the yardarms. They  are  used  in  sending  flashing  light  messages. The breakdown and man-overboard lights (red) for ships  are  32-point  (360°)  lights  located  6  feet  apart (vertically) and mounted on brackets that extend abaft the mast or structure and to port. This arrangement permits  visibility,  as  far  as  practicable,  throughout  360° of azimuth. The fixtures are spraytight and are equipped with 15-watt, 1-filament lamps. When these lights are used as a man-overboard signal, they are pulsed by a rotary snap switch (fitted with a crank handle) on the signal  and  anchor  light  supply  and  control  panel. The steering light (white) for ships is installed on the jackstaff or other spar or structure and must be visible to the helmsman in the pilothouse. The light is installed on the centerline if the pilothouse is on the centerline. If the pilothouse is not on the centerline, a vertical  plane  through  the  light  and  the  helmsman's station in the pilothouse must be parallel to the keel line. The fixture is spraytight and includes a disk screen with a 3/64- by 1-inch slot (opening) through which light is emitted  from  a  2-candlepower  lamp.  A  suitable  bracket is provided with which the light is mounted on a jackstaff  (1/2  inch  in  diameter). The stem light (blue) for ships is a 12-point (135”) light similar to the white stern light (fig. 2-16, view C) described previously. The light is installed near the stem on a ship that is engaged in convoy operations. It is mounted to show an unbroken arc of light from dead astern to 6 points on each side of the ship. The wake light (white) for ships is installed on the flagstaff or after part of the ship to illuminate the wake. It is so mounted that no part of the ship is illuminated. The fixture is tubular and spraytight. One end of the fixture has an internal screen with a l-inch-diameter hole  and  a  2  5/16-inch-diameter  by  3/8-inch-thick  lens, through  which  light  is  emitted  from  a  100-watt, 2-filament  lamp.  A  suitable  mounting  bracket  is included, with which the position of the light can be adjusted. Thus, the wake light puts a “target” in the ship's wake. Speed lights for the ships are combination red (top) and white (bottom), 32-point (360°) lights. They are at the truck (top) of the mainmast unless height of the foremast interferes with their visibility; in that case, they are located at the truck of the foremast. Two speed lights are installed if their light cannot be located so that they  are  visible  throughout  360°  of  azimuth. Speed lights are provided to indicate, by means of a coded signal (as in table 2-2), the speed of the vessel to other ships in formation. In other words, they indicate the order transmitted over the engine order system. The white  light  indicates  ahead  speeds.  The  red  light signifies  stopping  and  backing. The speed light is used as an aircraft warning light to provide a steady red light when the signal selector switch  is  placed  in  the  stop  position  and  the  circuit control  switch  in  the  aircraft  warning  position. ANCHOR  LIGHTS The forward and after anchor lights (white) for ships are 32-point (360°) lights. The forward anchor light is located at the top of the jackstaff or the forepart of the vessel; the after anchor light is at the top of the flagstaff. Each of the splashproof fixtures is provided with a 50-watt, 1-filament lamp. Anchor lights are energized  through  individual  on-off  rotary  snap switches  on  the  signal  and  anchor  light  supply  and control panel in the pilothouse. STANDING  LIGHTS Standing  lights  are  dim,  red  lights  installed throughout the interior of the ship or white lights installed on exterior deck passageways. The general purpose of standing lights is to provide the following: 1. In berthing spaces, the red lights provide just enough light to permit safe movement of personnel within   the   space   when   the   regular   lighting   is extinguished. 2. On the limited number of established routes between the berthing spaces and the weather stations, with reduced light contrast between the interior of the vessel and the dark outside deck. The purpose of the reduced light contrast is to reduce to a minimum the period  of  blindness  experienced  by  ship's  personnel going to stations on the outside deck. 2-14