A yellow towing light on a vessel signals towing operations under COLREGs.

Outline (quick skeleton to keep us on track)

• Hook: the water has its own language; a yellow glow is a clue.

• Quick refresher: COLREGs lights and what they signal.

• The yellow towing light: what it means, why it’s yellow, who uses it.

• Why it matters: safety, maneuverability, and clear signaling.

• Reading the scene on the water: scenarios with towing, examples, and how to react.

• Practical tips for mariners: what to do when you spot a tow.

• Quick memory aid and wrap-up: keep the yellow light in mind; stay safe.

Heading out on the water is a bit like driving at night in a busy city. Streetlights tell you when to slow, when to stop, and when someone might be turning. On the water, lights do the same job—only the signals come from ships, not cars. If you’ve ever wondered why a certain light looks different, you’re not alone. Today we’re zeroing in on one particular clue: the yellow light attached to a vessel. In the world of COLREGs—the International Regulations for Preventing Collisions at Sea—that yellow glow is a clear message: this vessel is towing.

Let me explain the basics first. In many parts of the world, ships are expected to show a set of standard navigation lights at night and in restricted visibility. You’ve got the white masthead light up front, the red and green sidelights, and the white stern light toward the back. These lights are like a code: tell you which way the vessel is pointing, how big it is, and how it’s moving. But there’s a special case, too: when a vessel is towing another vessel or an unpowered vessel, a towing light is added. That’s the yellow light you see. It’s not just color for color’s sake; it’s a deliberate, easy-to-see cue that something different is happening on the water.

What exactly does the yellow towing light signify?

• It signals towing operations. If a vessel is pulling another vessel or object, the yellow light is there to tell you that the power and steering may be constrained. Think of a tugboat tugging a barge; the situation is not the same as a lone motorboat or a small sailing craft.

• It sets expectations for maneuverability. A towed vessel doesn’t respond as quickly as a vessel that’s moving on its own. The towing vessel may not be able to turn or stop as swiftly as you’d expect. The yellow light helps other mariners anticipate that when you’re near, you’ll want extra space and a little extra time to avoid a close-quarters situation.

• It’s a distinct signal from other lights. The familiar white masthead, red/green sidelights, and white stern light tell you a vessel’s general direction and status. The yellow towing light is a special rider on top of that. It’s intentionally different so you can recognize “something towing” at a glance, even in rough weather or low visibility.

Why is the color yellow used? The color helps draw attention and reduces confusion. If you’ve ever watched traffic at a crossroads, you know certain colors carry specific meanings. The same idea applies on the water. Yellow is a clear, high-contrast color that stands out against night skies and dark hulls. It’s a subtle cue, but a powerful one, because it communicates a whole set of expectations without a long explanation.

Who uses the towing light, and when does it matter most?

• Tugboats and their tows. The image most people have in mind is a tug pulling a barge, or a tug assisting a larger vessel. In those cases, the towing light is the rule, not the exception.

• Any vessel towing a non-powered craft or vessel. If a vessel is being pulled, the towing light applies. The signal remains even if the towed vessel isn’t actively propelling itself.

• Night and restricted visibility scenarios. The towing light helps other mariners identify the unusual work going on and adjust course and speed accordingly.

Let’s connect the dots with real-life thinking. Imagine you’re approaching a busy harbor at dusk. A tug pushes a long line of barges, the water choppier than you’d like, the lights scattered across the scene. Suddenly you spot a yellow glow above the normal white and colored lights. Here’s what that tells you—without needing a paragraph of radio chatter:

• The vessel ahead is likely not maneuvering like a solo motorboat. It’s performing a towing operation, which means it may take longer to change direction or stop.

• Your safest move is to give it more room: reduce speed, keep a greater distance, and avoid cutting in close. If you’re passing, do so with ample clearance and communicate early if you’re in a crowded channel.

• If you’re on a crossing path, adjust your timing so that you don’t end up in a tight squeeze where sudden moves could be dangerous.

Reading lights on the water is part habit and part science. Here are a few practical tips to keep in mind so you stay on the safe side of the equation:

• Don’t assume every yellow light means “slow down.” It does, but more precisely it signals “watch out for towing activity.” Anticipate possible slow-downs, turns, or changes in the vessel’s path.

• In crowded channels, plan your approach well ahead. Use your radar and AIS where available, but always rely on visual cues too. The yellow tow light is your early warning in the dim hours or rough seas.

• If you’re piloting a small craft near a towing operation, maintain a bigger safety buffer than you normally would. The towed vessel might not respond promptly if a towing line or equipment shifts unexpectedly.

• Communicate when you can. A short radio call or a visible signal (when permitted) to confirm intentions can prevent a misunderstanding that could turn into a hazard.

• Remember that other lights still apply. The towing light doesn’t replace the masthead, sidelights, or stern light. It’s an addition that adds a layer of visibility and context.

A little memory aid helps here: think “yellow means tow.” It’s a quick shorthand you can keep in your head as you scan channels, rivers, and harbors. If you’re ever unsure what you’re seeing, you can cross-check with the vessel’s general light pattern, the time of day, and the expected traffic in the area. But the yellow light should stand out as the giveaway that towing is in play.

Curious minds often ask about the finer details or potential confusion. Here are a few clarifications that tend to pop up:

• A yellow towing light appears when a vessel is towing. It doesn’t replace other lights; it adds to them. So you may still see white masthead and stern lights along with the yellow towing light.

• The presence of a towing light doesn’t always tell you exactly what’s being towed. It signals “towing operations,” not the length or type of tow. If you need that level of detail for navigation, you’ll use other tools like charts or AIS data when available.

• Different regions may have slight variations in how lights are positioned, but the color and purpose of the towing light are consistently recognized in the COLREGs framework.

Let me explain why this matters beyond trivia. The water is a shared space, and everyone aboard has a responsibility to keep it safe. When a vessel is towing, it’s carrying a bit more risk in the mix. The yellow light is a cooperative signal that invites other mariners to adjust behavior in advance. It’s not about catching anyone out; it’s about preventing surprises—like a sudden swing of a tow line or an unexpected maneuver in a narrow channel. Respect for these signals keeps people, cargo, and crews safer, and it helps keep the rhythm of coastal life from becoming a chaotic whirl.

If you’re someone who loves maps, routes, and the poetry of a well-run harbor, you’ll appreciate how this single light fits into a bigger system. COLREGs are a set of rules designed to create predictability on the water. Lights, shapes, sound signals, and proper etiquette all work together like gears in a well-oiled machine. The yellow towing light is one small gear, but a crucial one. Read it right, and you’re less likely to find yourself in a tense close-quarters situation.

To wrap it up, here are three takeaways you can tuck away for future reference:

• A yellow towing light on a vessel tells you that the ship is engaged in towing operations and may not maneuver as a solo vessel would.

• This light is a distinct warning cue aimed at preventing collisions by signaling special circumstances to other mariners.

• When you see a towing light, slow down, give more space, and be prepared for slower or unexpected changes in the vessel’s path.

So next time you’re on the water, keep your eyes peeled for that yellow glow. It’s not just a color; it’s a message from the bridge to the helm of every other craft nearby. A simple, honest cue that helps everyone share the same lane, in the same language, under the same rules.

If you’re curious to learn more, you can explore the official COLREGs guidance and real-world navigational resources that break down light requirements and scenarios. The more you understand these signals, the more confidently you’ll handle the unexpected—on rivers, channels, or open seas. And that confidence is what makes a day on the water truly rewarding.