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Signaling & Visual

Navigation Light

Navigation lights are defined not by brightness but by exact range, colour and arc of visibility fixed in COLREG Annex I — a masthead light for a 60-metre ship must reach 6 nautical miles across a 225-degree arc, and a light that drifts outside either figure is non-compliant even while it still switches on.

Sealite
Knowledge

What to check on a Navigation Light.

100 models from Sealite in Navigation Light. Below: the full model list.

What sets navigation lights apart

Within signalling and visual equipment, navigation lights are the one category with hard numeric requirements written into an international convention rather than left to class or owner judgement. COLREG Rule 21 and Annex I fix the colour, minimum luminous range and arc of visibility for each light — masthead, sidelights, sternlight, towing light and all-round lights — by vessel length. A light that is bright enough to see but shows the wrong arc, the wrong colour chromaticity, or falls short of the required range for the vessel's length is not compliant, regardless of how it looks from the bridge. This is different from a floodlight or a signal lamp, where output and coverage are largely at the designer's discretion.

Navigation light arcs of visibility
Plan view of a ship's bow showing the masthead light forward arc, the port and starboard sidelight arcs meeting at the sector boundaries, and the stern light aft arc, each fixed by COLREG to an exact colour and angle.

Legend

  1. Masthead - white, 225 deg forward arc
  2. Port sidelight - red, 112.5 deg
  3. Starboard sidelight - green, 112.5 deg
  4. Stern light - white, 135 deg aft arc

Main components

Lantern housing and lens

A sealed housing holds the lamp or LED module behind a coloured lens (red, green, white or yellow depending on function) whose chromaticity coordinates are specified in Annex I. Salt film or scratching on the lens reduces effective range even when the light source itself is within spec.

Light source

Most new installations use LED modules rather than incandescent bulbs, giving longer service life and more stable output, but LED intensity degrades gradually with age rather than failing suddenly — a light can run for years below its rated range without an obvious full failure.

Read the full guide

Failure monitoring panel

SOLAS-required vessels carry a navigation light indicator panel on the bridge that shows each light's operating status and raises an alarm on failure. This panel, not visual observation from the bridge wing, is the practical means of knowing a light has gone out during a watch.

Selection and sizing

  • Required range by vessel length: for example a masthead light needs 6 nautical miles on vessels 50 m and over, down to 2 nautical miles under 12 m
  • Required arc of visibility: masthead 225°, sidelights 112.5° from dead ahead on each side, sternlight 135° astern, matched to the vessel's actual mast, funnel and superstructure layout so nothing blocks the arc
  • Type approval (wheelmark / MED certificate) confirming the unit meets Annex I photometric and chromaticity requirements as tested, not just as designed
  • Compatibility with the vessel's existing failure monitoring panel wiring and voltage

Regulations and class

COLREG 1972 Rules 20 to 31 set which lights a vessel must show depending on type, size and activity (underway, at anchor, towing, restricted in ability to manoeuvre), and Annex I fixes the technical detail — colour, intensity, range and arc — for each. SOLAS requires the failure alarm/indicator panel on applicable vessels. Equipment must carry wheelmark (EU) or equivalent flag-recognised type approval before installation; class surveys check the physical arcs are unobstructed as fitted, not just the equipment's paperwork.

Typical faults

CauseConsequence
Gradual LED intensity degradation with ageRange falls below the required minimum with no outright failure to trigger the alarm panel
Salt film or scratching on the lensReduced effective range and, on coloured lenses, drift outside the required chromaticity
New mast fitting, radar scanner or antenna installed after the original arc surveyPartial obstruction of the required arc that goes unnoticed until a near-miss investigation
Failure alarm panel miswired or bulb-based indicator burned outBridge unaware a light has failed during the watch, discovered only by another vessel or a port state inspection

What to look for in a supplier

  • Wheelmark or equivalent type approval certificate specific to the model, with the tested range and arc data attached
  • LED module replaceable as a spare part without replacing the whole lantern housing
  • Documented compatibility with the vessel's existing bridge indicator panel
  • Housing material and seal rating suited to the mounting position, since masthead units face far harsher weathering than lower sidelights

Test navigation lights against their rated range on a genuinely dark night with binoculars occasionally, not just for switch-on function at the dock — a light that switches on can still be running well under its required range.

Navigation light
Navigation light. Photo: Claudio Elias, Public domain, via Wikimedia Commons
Models

Models in this type.

The best-documented model of each manufacturer first, then the next — 100 of 100 models in Navigation Light. Every row links to full specifications, documents and service notes.

Showing only Sealite. Show all manufacturers
Sealite3NM Sealite3NM LED Barge Light Sealite5° SL-PEL-05/10° SL-PEL-10 SealiteBargeSafe™ 3NM SealiteSL-07 SealiteSL-07LB SealiteSL-125-1 SealiteSL-125-2 SealiteSL-125-3 SealiteSL-125-4 SealiteSL-15 All-Round SealiteSL-15 Anchor SealiteSL-15 Masthead SealiteSL-15 Port SealiteSL-15 Starboard SealiteSL-15 Stern SealiteSL-155 SealiteSL-155 All-Round SealiteSL-155 Anchor SealiteSL-155 Masthead SealiteSL-155 Port SealiteSL-155 Starboard SealiteSL-155 Stern SealiteSL-300-1D5 SealiteSL-300-1D5 2 SealiteSL-300-1D5-1 SealiteSL-300-1D5-1-W SealiteSL-300-1D5-2-W SealiteSL-300-2D5-1 SealiteSL-300-2D5-2 SealiteSL-310 All-Round SealiteSL-310 Anchor SealiteSL-310 Masthead SealiteSL-310 Port SealiteSL-310 Starboard SealiteSL-310 Stern SealiteSL-510-SA SealiteSL-60 All-Round SealiteSL-60 Anchor SealiteSL-60 Masthead SealiteSL-60 Port SealiteSL-60 Starboard SealiteSL-60 Stern SealiteSL-70 SealiteSL-75 SealiteSL-96 SealiteSL-96-1 SealiteSL-96-2 SealiteSL-96-3 SealiteSL-BR Series/SL-BR4 Series SealiteSL-BR-AC SealiteSL-C310 SealiteSL-C600 SealiteSL-ODSL SealiteSL-PEL-05 SealiteSL-PEL-10 SealiteSL-RL-04 SealiteSL-RL-Series SealiteAll-Round Red 2nm-C SealiteAll-Round Red 3nm-C SealiteAll-Round Red 5nm-C SealiteAll-Round Red 6nm-C SealiteAll-Round White 2nm-C SealiteAll-Round White 3nm-C SealiteAll-Round White 5nm-C SealiteAll-Round White 6nm-C SealiteAnchor 2nm-C SealiteAnchor 3nm-C SealiteAnchor 5nm-C SealiteAnchor 6nm-C SealiteFishing 2nm-C SealiteFishing 3nm-C SealiteFishing 5nm-C SealiteFishing 6nm-C SealiteMasthead 2nm-C SealiteMasthead 3nm-C SealiteMasthead 5nm-C SealiteMasthead 6nm-C SealiteNUC 2nm-C SealiteNUC 3nm-C SealiteNUC 5nm-C SealiteNUC 6nm-C SealitePort 2nm-C SealitePort 3nm-C SealitePort 5nm-C SealitePort 6nm-C SealiteStarboard 2nm-C SealiteStarboard 3nm-C SealiteStarboard 5nm-C SealiteStarboard 6nm-C SealiteStern 2nm-C SealiteStern 3nm-C SealiteStern 5nm-C SealiteStern 6nm-C SealiteTowing 2nm-C SealiteTowing 3nm-C SealiteTowing 5nm-C SealiteTowing 6nm-C SealiteSolar 2NM SealiteSolar 3NM
100 models
Related types

Also in Signaling & Visual.

The other equipment types in this category.

Daylight Signaling LampFlag Signal EquipmentFog Horn / Sound SignalNavigation LightsSearchlightSignal LightSound Reception System
More than the data sheet shows

Write to us about this model — the answer comes by e-mail.

Name the make and the model and what the job is: a spare, a service call, a second opinion on a data sheet. We answer by e-mail.

No details at hand? A photo of the rating plate or the part is enough — simply attach it to the request.

Frequently asked

Questions that come up with this equipment.

Is Navigation Light data free?

Yes. Every model page, every guide and every datasheet for this type is readable without an account. An account adds saved searches and requests, nothing is taken away.

My model is missing — what now?

Send us the nameplate. We identify it by hand, add it to the library, and if you need a part or a service, the request is already on our desk.

Can you source a Navigation Light part?

Yes. Tell us the manufacturer, the model and what you need — a person reads every request and replies by e-mail.