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US Coast Guard Auxiliary, Flotilla 10-2, Savannah Georgia, 7th CG District

Navigation Lights

Navigation Lights

If you're going to go out at night, you've got to be able to recognize the lights you see. Lighting can get pretty confusing. First of all, there are city lights, house lights, lights from cars, then lights from navigational aids, hand held lights, stars above, as well as the lights from boats - which we will discuss here. To make things a tad bit more interesting, boats have various classifications based on their ability to maneuver.

Here's the "pecking order" of boats. (Those above your vessel-type are "stand-on" vessels. Yours, and any vessel-types below yours, are "give-way" vessels in any meeting situation.):

A little mnemonic saying which will help you remember this is, "New Reels Catch Fish, So Purchase Some Willingly".

In order to know whether you are the "stand-on" or "give-way" vessel in a meeting situation, you must first know what type of vessel you have and what type of vessel you are meeting. Those higher on the list are deemed the "stand-on vessel" (see the Nav Rules). At night (in unrestricted visibility), a vessel's type is designated via its lighting. In restricted visibility (day or night), it is done with sound signals. During the day in unrestricted visibility, it is done with day shapes.

Perhaps we should define those terms:

NUC (Not Under Command)
A disabled vessel, not able to maneuver normally.
RAM (Restricted Against Maneuverability)
A vessel that is restricted in her ability to maneuver, due to THE NATURE OF HER WORK. These include minesweepers, buoy tenders, some towing vessels, etc.
CBD (Constrained By Draft)
Vessels who cannot move to the side in a deep channel. This designation only applies to international rules. There are no CBDs in US inland waters (inside the line of demarcation.)
Fishing
This refers to commercial fishing, not sport fishermen who are trolling. They should still be able to maneuver to get out of the way of other power vessels. (Courtesy, however, might yield to a fishing vessel that has a fish on the line.)
Fishing (Trawling)
Shrimp boats, that have their nets deployed. Otherwise, shrimp boats are simply powerboats.
Sailboats
Sailboats that are not operating mechanical propulsion (engines) have prescidence over power vessels. Once they engage their engines, they become power boats, even if their sails are up.
Powerboats
Vessels, not of the previous types, that are operating mechanical propulsion.
Seaplanes
Seaplanes that land or take off on water, must yield to all other craft.
WIG (Wing In Ground)
A new designation for water transport vessels that operate much like aircraft, but generate lift by flying just above the water, taking advantage of "ground effect", where the wings compress the air against the "ground" or surface of the water.

Sidelights
Red and green lights are to be displayed from dead ahead to "two points abaft the beam". One "point" is 11.25 degrees; two points are therefore 22.5°. The beam is straight sideways, or 90° from the bow. So two points abaft the beam means that each light will shine over an arc of 112.5° (90°+22.5°=112.5°). Red on port (left side of boat), green on starboard. (Think of red port wine as a reminder.) Combined, the red and green sidelights (or ‘navigation lights’) shine over an arc of 225°.
Masthead lights
White lights mounted on "the mast" (or center line of boat) which shine over an arc of 225 ° (the same area as the sidelights combined). Power vessels 50m and greater are required to have a forward and aft mastlight, the aft being taller. (The alignment of the two point the direction of forward movement.)
Stern lights
The remaining degrees of the compass (360°-225° = 135°) are reserved for the stern lights. These are white lights which point dead astern (66.5° either side of the keel line - 66.5°+66.5°=135°). Note, when overtaking a vessel, the stern light should appear to extinguish at the same time the sidelight becomes visible.
Flashing lights
Flashes twice per second. Yellow color.
Towing lights
Yellow 135° light placed over stern light when towing astern.
All Around Lights
Shows 360°. White, red, or green. Used to show designation (NUC, RAM, CBD, etc.) or that boat is anchored.
Anchor light(s)
White All Around Light. Only 1 light is required for power vessels < 50m, 2 if >= 50m. If 2, the aft light is lower than the forward light (different than masthead running lights, where the aft is higher). When anchored, the running and stern lights aren't lit, only the all around anchor light(s) plus any designation lights.
Tricolor
Red and Green side lights plus stern light combined in one light. This is an alternate means for a sailboat to show its navigation lights from the top of the mast.

Now for the fun stuff. The COLREGS (Collision [Avoidance] Regulations or "Nav Rules") specify that each type of boat be required to display characteristic lighting. In addition to the types listed above, special lights are designated for tow boats and their tow, anchored boats, shrimp boats vs trawlers, hovercraft and hydrofoils, submarines, vessels 50m and greater, power vessels under 50m, power vessels less than 12m, and vessels less than 7m capable of less than 7 knots. During the day, they show their status with "dayshapes". Day shapes are always black. Here's how that all falls out:

Vessel Type Dayshape Side Lights Masthead Stern Lights Anchor Lights Special
NUC

(running)
0

(running)
see power
RAM

(running)
see power
(running)
0
RAM
Dredge)

(running)
see power
(running)
0
RAM
(Minesweeper)

(running)
see power

(running)
see power
CBD
see sail/power see sail/power see sail/power see sail/power
Fishing
(Trawling)

(running)
see power
(running)
0
Fishing
(Not trawling)

(gear >200M)

(running)

(forward)

(running)
0
Sailboat

(running)
0
(1=power)

(running)
optional
Sailboat
<50m (Option)
0 0
(1=power)

(running)
Power
>=50m
(none)

(running)

(running)
Power
<=50m
(none)

(running)

(running)
Hovercraft
Hydrofoil/WIG
(none)

(running)
see power

(running)
see power
(forward)
Tow boat
<200m hauser (short tow)
(none)

(running)

(running)
Tow boat
>=200m hauser (long tow)
(diamond-tow & barge)

(running)

(running)


How to remember all those special lights?? Here's a few hints.

NUC Red over Red, the captain is dead.
 
RAM Red,White,Red, the work I dread.
 
CBD Three reds in a row, no clearance below.
 
Fishing - Trawling Green over white, shrimping tonight
 
Fishing - Not trawling Red over white, fishing tonight
 
Sailing Red over green, sailing machine
 
Pilot White over Red, Pilot ahead

One more - Dredge pipes are illuminated with yellow flashing lights,
but gaps are provided for safe passage and will have two red lights on each side. Always pass a dredge at idle speed and contact the captain by radio if you have any misgivings.


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