Steve D’Antonio Running lights at the bow pulpit on a sailboat. When under power, these conventional deck-level lights must be used; under sail, a mast-head tricolor is used.
Navigation lights, the best protection against nighttime collisions, are worth getting right.
In my work inspecting boats, I routinely encounter noncompliant navigation light installations on new and preowned vessels. Often, when I bring this to the builder’s attention, they are defensive. The near universal response: “We’ve been doing it this way for years; you are the first person to point this out.” When I share with them the literal chapter and verse from the U.S. Coast Guard Navigation Rules, and/or ABYC’s A-16, Electric Navigation Lights, the defensiveness usually gives way to, “How could that be?” and then, “How do we fix this?”
Most are truly cases of not knowing better (exactly what we aim to remedy in these pages), while a few plow their proverbial heads into the sand and insist that their way is fine. I tell them this: “If your vessel, the one you built with noncompliant navigation lights, is involved in a nighttime collision, including being run down even if yours is legally the stand-on vessel, the operator could be assigned a portion of blame. If there’s a serious injury or death, or significant property damage, you’ll likely be drawn into the event legally. Why risk this if you can make the lights compliant?”
Compliance means following the rules, but because they are written in what can often be very difficult to understand maritime legalese, I understand why boatbuilders and other industry professionals often get navigation lights wrong. For this article, I had to digest, interpret, and translate these regulations to be sure I had a thorough understanding of the subject. Then, I scrutinized multiple navigation light installations.
Steve D’Antonio The fine print on this stern light specifies its compliance with COLREGS requirements; however, the adjacent stern rail support obscures the full arc of illumination, making the light noncompliant.
It comes as a surprise to many boat owners that boatbuilders are not obligated to install navigation lights. However, if lights are installed by a builder (or a yard or boat owner) and the vessel is sold or operated in the United States, regardless of where it is manufactured, then those lights must comply with established standards. As for international regulations, they are largely harmonized worldwide, thanks to the Convention on the International Regulations for Preventing Collisions at Sea (72 COLREGS), the international body that establishes guidelines for navigation lights, including how they are displayed, their range, and their construction.
The surest way to avoid a nighttime collision or being run down is to be seen. And being seen is easily accomplished with navigation lights, especially running lights in good working order and compliant with U.S. Coast Guard Navigation Rules and ABYC A-16 guidelines. (These are essentially the same, although only the former is legally binding.) I’m surprised and disappointed at the number of vessels I inspect whose running lights are inoperable, in a poor state of repair, obstructed, or improperly installed. In many cases, incorrect placement is the result of boatbuilder errors. You can’t assume a boat’s navigation lights are correct just because it’s new or because navigation lights are original equipment installations.
On a recent inspection of a new vessel at the builder’s yard, I found a steaming (masthead) light with range insufficient for the vessel’s length. It was a 3-nautical mile (nm) light on a boat exceeding 65′ (19.8m), which requires a light with a 5-nm range.
Navigation light requirements, including configuration, placement, and intensity or range, are driven by vessel length, with distinct specifications for the following ranges: Up to 7m (23′), from there to 12m (39.4′), from there to 20m (65.6′), and finally, to 50m (164′). For detailed requirements and definitions, consult the full Coast Guard regulations.
Steve D’Antonio Be sure a light’s rated range (2 nautical miles in this case) satisfies the Coast Guard’s requirements for the vessel length.
Whether or not a designer has provided complete wiring details for all systems, new build and refit yards can plan a basic navigation light installation as needed. First, construct a line drawing of the vessel with the location of each navigation light. Specify and label each light, in addition to the type, size, and number of conductors in each cable. If space permits, when laying out the cable that will lead to the masthead, arch, or cabintop, include additional conductors for likely future installations. For example, it’s reasonable to plan that the masthead will be equipped with tricolor (for sailing vessels) and anchor lights. But your plan should accommodate a strobe or wind indicator illuminator to be added. This would require a cable consisting of five conductors: ground, anchor, tricolor, and two spares for future use.
The gauge of the conductors will depend on the total run, from electrical panel to masthead (in this instance) and back. Note that in vessels equipped with LED navigation lights (and wind indicator illuminators), it’s virtually impossible to use a cable that is too small. This light source is so miserly with its electrical consumption, requiring just a fraction of the energy needed for conventional incandescent light bulbs, that even the smallest allowable wire size (ABYC calls for a minimum of 16-gauge wire for most onboard applications) will usually fall within the maximum 3% voltage drop with capacity to spare.
Defects and Other Considerations for Builders
The most frequent installation defects that come straight from boatbuilders are in placement and mounting. To assess a boat’s navigation lights, look closely at each light fixture, including those on and at the top of the mast for sailing vessels. Depending on a recreational vessel’s size and sail/power configuration, there may be as many as six, including port, starboard, stern, steaming/masthead, tricolor/strobe (for sail), and anchor or all-round. Ensure that none is obstructed. Unanticipated visual interference is common from davit-hung tenders and other stern-mounted gear, as well as mast-mounted radar domes, antennas, radar reflectors, solar panels, and even flags. In some cases, the transom structure may block a portion of a stern light’s arc.
Most navigation light manufacturers specify orientation, either in the installation instructions or with an “UP” or “TOP” marking. Even if the visual effect and light distribution appear to be the same either way up, lights should not be installed upside down, as water may accumulate within.
Builders and buyers should be certain that sidelights are mounted on vertical surfaces, parallel with centerline and level when the vessel is at rest. Stern and masthead lights should be vertical and mounted perpendicular to the vessel’s centerline. Sidelights mounted on converging bow rails not parallel with the vessel’s centerline have the effect of displaying overlapping red and green arcs ahead, making it seem to traffic at a close forward bearing as if the vessel is bearing directly down on them, when in fact it may not be. I frequently encounter this flaw on tenders whose sidelights are mounted on the curved sides of center consoles. (Sidelights mounted on tender consoles are often also obstructed by passengers.)
Steve D’Antonio Sidelights mounted on curved center consoles are often out of alignment and easily obstructed by passengers.
Depending on the orientation of the surface they are mounted on, lights may need to be shimmed to ensure they are vertical and parallel to the centerline.
To comply with the 72 COLREGS, the Inland Navigation Rules, and their Annexes, found in the U.S. Code of Federal Regulations (33 CFR Subchapter E), sidelights should be installed above the sheerline (this is the top edge of the hull side defined by the caprail or toerail on many vessels). I strongly recommend avoiding installing sidelights in or on the hull where they are less visible, particularly when heeled, and they are exposed to more spray and immersion, reducing reliability.
I commonly encounter vessels longer than 12m (39′) whose builders have installed a single white all-round light, rather than separate masthead and stern lights—a clear violation of regulations.
Steve D’Antonio Sidelights should be installed above the sheerline and be shimmed to ensure proper placement relative to the centerline.
Remember, as well, that for sailing vessels, tricolor lights can only be used when under sail (not motor-sailing). While under power, conventional deck-level lights must be used, and at no time should both sets of lights shine simultaneously. To avoid this error, consider installing a two-position switch with power supplied by a navigation light circuit breaker that will activate either the steaming or sailing configuration, but not both.
For vessels registered or operating in the United States, when selecting, inspecting, or replacing navigation lights, make certain they carry a U.S. Coast Guard approval permanently stamped, printed, embossed, or debossed on the fixture (it cannot be a decal), and ensure it’s appropriate for the vessel’s length.
* From the U.S. Code of Federal Regulations: Per 183.810: Boat manufacturers must install navigation lights that meet all technical standards (as proven by testing at a USCG approved laboratory) and bear a permanent and indelible marking “USCG” followed by the certified range in nautical miles (ex. USCG 2nm). The marking must be visible without removing or disassembling the light.
As a practical consideration, when I contemplate disassembling a light housing with a small screwdriver while hanging over a bow rail or swinging in a bosun’s chair, I realize that I prefer fixtures that can be serviced without tools. And during servicing of incandescent fixtures, which are becoming less common, make certain the correct wattage bulb has been fitted.
While modern LED lights are virtually immune to bulb failure, they are no less prone to wiring and connection issues. In any build or refit, be certain all navigation light wiring connections are fully waterproofed with heat-shrink crimped connections and/or sealant. Used in conjunction with dielectric grease, these crimped connections yield a long-lasting, low-resistance, corrosion-resistant connection. The primary drawback to heat-shrink connectors is the suppleness of the heat-sensitive insulation; it can easily be damaged by the incorrect crimping tool or die size. Use caution in performing this task, and inspect your finished work carefully for weathertight integrity.
Steve D’Antonio Wire unions should be properly sealed with heat-shrink crimped connectors to protect them from moisture. These have been compromised by incorrect crimping.
Most navigation light failures (that aren’t a bulb) are related to corroded or stressed connections. Mast-mounted lights are especially prone to the latter. Be sure the considerable weight of the wire is not supported by the light fixture or connection/splice. And, ideally, it should be protected within a conduit inside the spar. Support the wire using wire ties (black if exposed to UV rays) with support-screw provisions or P-clips wherever possible. Purpose-made grommets, ample amounts of silicone sealant, a quality electrical tape, and UV-resistant hose are handy aids for wire protection. Chafe is an ever-present threat, particularly where wires are run around hard metal structures such as masts and arches, or metal frames and stringers aboard steel or aluminum vessels.
If the cables exit a mast or arch above the deck, a suitable through-deck fitting must be used—either a chrome-plated brass fitting with rubber packing and a knurled or hex nut, or a modern alternative of high-impact plastic, synthetic rubber, and stainless-steel screws. The latter requires a bit more labor to install, but if done correctly is virtually leak-proof and reduces the likelihood of cable damage. These through-deck fittings are available in several sizes to accommodate everything from RG-58 coaxial cable (about the size of a pencil) and smaller wires, up to larger radar cable sizes. They also work where deck-level navigation light wiring must pass through the hull or deck.
While LEDs have been a boon to the industry, there have been failures, especially among some early marine applications. Check the vintage and functionality of LEDs on client vessels in your care. With varying degrees of sensitivity among different manufacturers, some LED navigation lights can be damaged by exposure to higher voltages than may be normal from sophisticated, high-output charging systems. Be certain the lights you are using or selecting can handle the highest normally anticipated charging system voltage on the vessel’s electrical system. Many, but not all, LED light manufacturers have broadened the acceptable voltage range to remedy this issue in recent years.
While aftermarket replacement bulbs have become popular for converting cabin and other lighting from halogen and incandescent to cooler and more efficient LEDs, replacing a conventional navigation light’s incandescent bulb with anything other than what has been specified by the fixture’s original equipment manufacturer will, regardless of improved efficiency and lifespan, result in a noncompliant navigation light. That’s because the testing carried out by the Coast Guard yields a certification that is valid for the complete light fixture, with its original equipment bulb. Using anything other than this, regardless of advertised claims of U.S. Coast Guard compliance, will force your navigation light fixture out of compliance. If such an arrangement is being used and a collision occurs, the operator of the vessel with noncompliant lights may be found to bear some fault for the accident even if the lights were fully operational.
Inspecting Navigation Light Wiring
Setting original equipment installation errors aside, if navigation lights fail on a boat in your care, it’s time to inspect the entire system and replace any elements necessary. Even if you haven’t had problems, an inspection of the wiring and fixtures on an older boat is advisable.
Begin by thoroughly inspecting all visible wiring in the navigation light circuits and fixtures. These include running lights, steaming light, masthead tricolor on sailboats, anchor light, masthead emergency strobe, and while you’re checking mast wiring, look at any spreader lights, deck lights, and the VHF antenna, too. Concentrate on terminations, connections, and terminal strips, particularly those that may be exposed to the elements, bilge water splash, or simply the damp environment found adjacent to bilges and other normally closed spaces.
Steve D’Antonio Wiring inside of sailboat masts should be run through a conduit.
On a modern sailboat, most of these wires will be contained within the mast, preferably in a conduit, or in chases or bundles. In powerboats they will be run under deck or cabin structures to the light fixtures. You can learn a lot by inspecting the visible wiring at each fixture and where it exits at the foot of a mast and around likely chafe points in the wire run.
Steve D’Antonio This wiring exiting the base of the mast is appropriately bundled and wire-tied but should have chafe protection where it bears against hard metal mast and frame structures.
Look closely at the wiring for clues or indicators that may lead you to the cause of the failure. Is the outer insulation cover gray? If so, unless the jacket is specifically marked as UL Boat Cable, the wiring within is likely not marine grade, which means that conductors are not tinned (tinned wire is good practice but not required for ABYC compliance), their strands may not be fine enough for requisite flexibility, and the insulation is not stable in prolonged direct sunlight. Such wiring, meeting automotive rather than marine standards, was quite common on boats until the late 1990s. It remains popular with many do-it-yourselfers primarily because it’s easily obtained and less expensive than tinned marine wire. This is not to say that non-Boat Cable is unacceptable, but it should be taken into account in your inspection; products that do not meet Boat Cable standards are more likely to succumb to UV-light degradation and corrosion.
Steve D’Antonio Look for wiring to be labeled UL Boat Cable to ensure that it’s marine grade.
No matter the color, if the insulation appears cracked, brittle, chafed, or severely discolored, the wire within may be damaged and therefore unreliable. Replace the cable.
It is prudent to incorporate a “drip” or “service” loop into some fixture installations to allow water to drip off the cable instead of running down into the mast or fixture. And if a connector must be replaced, this service loop will provide that extra inch of cable required to make future repairs. Be sure to make the loop using a generous radius to prevent overstressing the conductors.
Next, focus on the light fixtures themselves. They should be mechanically sound and well-fastened to the mast, rail, cabin, or hull. If the lenses are faded, cracked, or otherwise dam-aged, or if water has condensed on the inside of the lens, repair or replace them. (Note that LED fixtures are not immune to these failures.)
Check the bulbs. If the glass is loose from its metal base, then it’s suspect and should be preemptively replaced, even if it does work. If the base is bare brass (it may look tarnished but is gold in color), chances are it was designed as an automobile parking light rather than for a life at sea. Dedicated marine light bulbs always have a silver-colored base that is tin-plated and, therefore, corrosion-resistant. This base will be far more reliable than its untinned counterpart. For further corrosion protection, wipe a light coating of dielectric grease (clear silicone greases are usually suitable for this purpose) on the bulb’s base and contact surfaces. This will exclude air and any moisture that might make its way into the fixture.
Once you have located the failures and weaknesses and made the necessary corrections and replacements—lights are installed, mast is stepped, arch installed and wired, etc.—test the system thoroughly. Be sure all lights function from their designated switches, and conduct a VHF radio check to a station more than 10 miles away to rule out interference. Lastly, stock spare bulbs for each incandescent light fixture on board.
About the Author: For many years a full-service yard manager, Steve now works with boatbuilders and owners and others in the industry as Steve D’Antonio Marine Consulting. He is an ABYC-certified Master Technician and sits on that organization’s Engine and Powertrain, Electrical, and Hull Piping Project Technical Committees. He is also technical editor of Professional BoatBuilder.
LED Lights, Radio Frequency ‘Noise’
The American Boat & Yacht Council’s guidance on radio frequency interference from LED navigation lights follows:
“Navigation lights and other deck and mast-mounted lighting equipped with light-emitting diodes (LEDs), including those certified to recognized Electromagnetic Compatibility (EMC) standards, have been found to cause debilitating interference to very high frequency (VHF) radiotelephones and automatic identification systems (AIS) without operator awareness. Degradation of radio communication and the AIS signal may compromise vessel safety if the problem is not corrected.
Interference to GPS receivers is also possible. Periodic EMC checks are therefore essential, especially after installation of LED-equipped lighting or other systems mounted near antennas susceptible to unintentional interference.”
Definitions for Navigation Light Regulations
Length Overall (LOA)—The straight-line measurement from the foremost part of the vessel to the aftermost part of the boat, measured parallel to the centerline and to the design waterline. Integrally formed, molded, or welded components and appendages, such as bow pulpits, swim platforms, attachment structures for the propulsion systems, and structural rub rails installed by the builder are included in the length (author’s emphasis). Attached bowsprits, pulpits, boomkins, rudders, sails, outboard brackets, handles, railings, and other similar attached extensions are not included in the measurement.
All-Round Light—Unbroken light over an arc of the horizon of 360°.
Combination Sidelight—Navigation light fixture in which sidelights are combined into one lantern.
Masthead Light (often called steaming light)—White light placed over the fore-and-aft centerline showing an unbroken light over an arc of the horizon of 225°, fixed to show the light from dead ahead to 22.5° abaft the beam (90° + 22.5°= 112.5°) on both sides of the vessel.
Sidelight—Starboard navigation light showing green, and the port navigation light showing red, from straight ahead to 22.5° abaft the beam (90° + 22.5° = 112.5°) on their respective sides.
Stern Light—White light placed as close as practicable to the stern showing an unbroken light over an arc of the horizon of 135° and fixed to show the light 67.5° from directly aft on each side of the vessel.
Tricolor Light—Single navigation light fixture in which sidelights and stern light are combined in one lantern.
Strobe—Flashing strobe lights are not considered navigation lights and may not be used as such. They can be used in emergency scenarios to attract attention of nearby vessels.
