Page 209 - NAVAL SCIENCE 3 TEXTBOOK

RU LES Or T HE ROAD AND :-'IANEUVER ING BOAR D 21S

Running Lights Other Lights and Day S hapes
\Vhite, red, and green lights shown by all vessels under way at In addition to the Ilormalunderw;'l), lights described above, there
night or in pOOl' visibility conditions are called I"II/Illillg lights. The are several other special combinations of lights and day shapes
white light in the tore part of <l ship is called the lIll1st},earllight; it (geometric shapes like balls, cones, and diamonds, made from
is required for all oceangoing vessels, The white light 0 11 an after- canvas stretched over metal ribbing) for vessels engaged in certain
Illast is called the mllge light; it is required only 011 vessels 50 meters activities or in a special status.
( feet) or Illore in length. The port sidelight is red, nnd the star- ~'Iost harbors require large ships to take aboard il pilot who is
board sidelight is green. A ,'esse! under way mllst also display a thoroughly familiar with the harbor, berthing instructions. and the
white stern light. handling of local tugboats. to take the ship into port. When enter-
The purpose of these lights is to Wilrn vessels of the presence or ing port at night. an officer of the deck (OOll) or conning officer
approach of other \tessels and to show in which direction they arc of a ship will wnnt to know the inst;'l11t the pilot boat is sighted so it
going. On i.l dark night, it is nearly impossible to see illl}'thing of a ma), be signaled alongside. "White over red. pilot ahead" is the little
ship or boat except the running lights. The sidelights Me arranged memory aid to use when looking for the special ideJlti~'ing lights
so that when both the red and green sidelights are seen, you are of a power-driven pilot boal at night.
looking at the bow. and the vessel is hending directly toward you. All vessels O\'el" 7 meters (23 feet) long at anchor must show
\"'hen onl}' the green sidelight is seen, you are looking at the st .. 11"- il11chor lights, according to the rules. Vessels less than 50 meters in
board side, somewhere from the bow to slightly behind the star- length ill nnchor show <1n all-around white light forward. If more
board beam. When anI), the red sidelight is seen. )'on are looking thiln 50 meters, n similar light aft must be shown also. The forward
at the port side, somewhere from the bow to abaft the port beam. light should be higher than the onc aft. usuall), on the top of the
The masthead and range lights have the same arcs of visibility as jackstall" at the bow of a ship. Powerboats and sailboats typicall),
the sidelights, and reinforce the ability to determine what aspect of display their anchor light from their mast-top.
the vessel you are seeing (See the diagram of the arcs of visibility.) In the daytime, all vessels over 7 meters long at anchor must
displa)' a black ball da), shapc. The black ball is displa),ed in the for-
ward part of the vcssel, usually from a crosstrec of the mast where
WHITE MASTHEAD UGHT
225' it is clearly visible frOlll all directiolls.
(MAY BE AlL·AROUND UGHT FOR
VESSELS LESS THAN 12 METERS) Vessels towing mllst display two masthead lights in a vertical
line. If the tow extends be)'ond 200 mcters (656 leet) astern of the
REO~OEUGHT GREEN ~DEUGHT towing vessel. a third light must be displayed below the second light.
112.5° 112.5°
By dOl),. if the Icngth of the tow exceeds 200 meters. a black diamond
shape is hoisted on the towing vessel (international rules) and the
tow where best seen.
In both sets of rules the term "not under cOlllllland" refers to
/
WHilE STERN UGHT ships nnd craft that are disabled and cannol operate in accordance
135'
WHITE AFTER MASTHEAD (RANGE) LIGHT with the rules. A vessel not under cOIllIll~l1ld at night must show
FDA VESSELS LQ,'1GER THAN 50 METERS
225' two red lights, one over the other. If a power-driven vessel with
headway, the vessel mllst show the not-under-command lights
Diagram of the arcs of visi bil ity for masthead, sidelights, and stern
instead of the masthead light, as well as its sidelights and stern
lights, for both international and inland rules.
light. During da),light. a merchant ship hoists two black balls. A
nnv;.ll vessel hoists the "5" flag if it is not under command and ",ill
The obsen'ed pattern of the white masthead and range lights, also hoist two black balls as a warning to any merchant vessels if in
together with the sidelights, indicate the comse of a sighted ship or international waters.
boat. The white stern light warns overtaking vessels that another Other lights and day shapes arc prescribed lor various special-
\'esscI is ahead. On oceangoing vessels 50 meters or more in length, ized operations such as cOlllmercial fishing, cable laying. underwa-
the upper white lights must be visible from il distance of at lenst 6 ter or diving operations, ilnd dredging. The interested student may
miles. The port and starboard sidelights ilnd the stern light must find all these rules in books covering the complete rules, published
be visible nt least 3 miles away. Running lights on smaller vessels b)' both private publishers and the Coast Guard. ,wailable at most
have somewhat lower range requirements. nautical supply stores and large libraries i1l1d bookstores.
The international rules and the inland mil's agree in the i.lrCS of
visibility required of the lights shown. Power-driven motorboats
require similar lights, but the rnnge light is optional.