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In the Dark About Lights?

It’s too easy to take your navigation lights for granted until something fails or gets obscured
Know your nav light patterns, especially the difference between tugs towing astern and alongside or pushing ahead.

Know your nav light patterns, especially the difference between tugs towing astern and alongside or pushing ahead.

Back in the day, ships were small enough for the bow lookout to turn, face aft and yell back to the mate on the bridge. A sailor would affirm the correct functioning of the navigation lights each day at sunset by shouting, “The lights are shining brightly!” I loved this old-timey routine. You can call me a nostalgic old toot, but I fondly recite the words under my breath before assuming a night watch to this day, no matter what boat I’m on.

Checking to make sure your navigational lights are functioning every sunset underway is just plain good seamanship. This past summer, two recreational boaters were killed and three others were injured on the Great Lakes when a vessel collided with an unlit boat underway on a dark and moonless night. This accident should have been totally avoidable. Unfortunately, the operator failed to ensure the navigation lights were on and functioning correctly.

Not only do your lights have to be turned on from sunset to sunrise, but you and your crew also have to know how to read others’ lights. Another accident, on Long Island Sound some years ago, still haunts me as an example of why. On a dark night, the owner-operator of a sportfishing boat misinterpreted a towboat’s lighting configuration and crossed behind the tug towing astern. He fouled the towing cable, which placed him—mechanically disabled—straight in the track of the barge lumbering along at the end of the tow. Tragically, the barge ran the sportfisherman down, forcing the boat and the passengers underwater. The accident killed almost everyone on board.

Know your navigation light patterns, especially the difference between tugs towing astern and alongside or pushing ahead. In addition to studying the rule book, if you or your crew need to hone your after-dark skills, then study traffic at dusk or dawn. That way, light configurations and the vessels carrying them can be seen together. At these times of day, the changing aspects of masthead lights, the moment sidelights become or stop being visible, the shape and size of the vessels, and the placement of their lights will be readily apparent. Navigation lights that indicate passing, crossing, overtaking and rights of way will make perfect sense. Tugs will reveal their towing light patterns (international and inland) and barges will show themselves at the end of a stern tow with low-to-the-water sidelights.

As a young sailor, I practiced with a knowledgeable mariner. It went something like this: “What do you see up there fine on the starboard bow?” With binoculars glued to my eye sockets, I’d verbalize the applicable mnemonics. “White over red, pilot ahead,” versus “red over white, fishing at night.” The point is that it doesn’t matter whether you use an app, read and study the illustrations in the rule book, exercise with flash cards, or memorize ditties. Just practice until your skills are solid.

Train your senses to anticipate common patterns. Some are nuanced, and some are vivid alerts. The distance between a vessel’s masthead lights indicates the length of a ship, and the relative changes in that distance shows a change in heading. Of course, if you see both white lights in line vertically, combined with red and green sidelights, then that boat is bearing right down on you.

Making out navigation lights against a complicated harbor layout or urban shoreline can be challenging. Look for clues such as black silhouettes obscuring the background lights, and then focus to decipher a light pattern amid the backdrop.

And anticipate what to look for in channels. These are situations where it’s prudent to have two people on watch and/or a dedicated lookout. Of course, use your electronics as well, but don’t rely on them alone. Having visual skills and learning to rely on your senses make you the best seaman you can be.

Maintaining your own vessel’s navigation lights is as important as knowing how to use them. Preventive maintenance saves lots of aggravation, so make a periodic inspection of all your lights. Look for water intrusion, cracked lenses, deteriorated O-rings, corrosion and cracked or loose wires.

Ensure that arc of visibility shielding devices are effective. The visible sectors of your lights determine your legal right of way—or another boater’s—and they must be correct. While you’re at it, take an inventory of all navigation light bulbs, ensuring that you have correct spares of the required wattage. Label them so they are immediately identifiable when you need one.

Of course, there’s no way to predict when a light bulb will blow out. On large and luxury vessels, navigation lights have two bulbs, so a crewmember merely has to flip a switch to energize the backup. As for the rest of us, “know before you go” is, as always, a good mantra. Testing navigation lights before getting underway is good practice; I guarantee you’ll be happy to discover a bad light before you leave the harbor. Who among us prefers to cling to the cabin side like a horsefly or go aloft in a bosun’s chair in a seaway?

Also, make sure your lights are unobstructed and unimpaired. Do you know what your light configuration looks like to others when you are underway? Could anything you may have stowed on deck, such as a paddleboard or water toy, obstruct one of your navigation lights? Check out your boat from the dinghy or at the dock to make sure.

Your navigation lights should be unmistakable and properly displayed. I emphasize properly because last month, we were sailing along as it was getting dark and saw a masthead white light blinking a distinctive SOS. As we approached the sailboat, the boaters waved happily and raised their glasses in a toast to us, completely oblivious that they were sending a distress signal.

The same advice applies to having your anchor or strobe light on while underway, or to running with halogen headlights or bar lights turned on. More is not better. The objective is to communicate a clear, unmistakable message, letting others know your size and type of vessel and heading, and the right of way status to the other vessels around you.

Cruise ships are notorious offenders. With several thousand people aboard in full party mode, disco lights and alternating rainbow spotlights flashing merrily all over the deck and superstructure, they sometimes make it a challenge to locate their sidelights and discern one end of the ship from the other.

For sailors without helm electronics (you’d be surprised how many of those there are offshore), it’s difficult to gauge the speed and heading of a large cruise ship. The ships often dog along at night, making bare steerageway for a timed port arrival. When in doubt, slow down or stop and let the ship pass. Doing so certainly livens up an otherwise uneventful watch.

It’s all too easy to take your navigation lights for granted until something fails or gets mistakenly obscured. The consequences could be dire when there is a failure, so it’s imperative that your vessel’s lights are kept in good condition. Checking on and maintaining reliable navigational lights is a great habit to nurture, and your proficiency in interpreting others’ lights is essential to avoid becoming another accident statistic.

This article originally appeared in the January 2020 issue.

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