Which vessel gives way in a crossing? Understanding red-light cues and right-of-way under COLREGs

Red light, green light on the water: how the crossing rule really works

Ever stood at a busy marina and watched two boats creep toward each other like cars at a four-way stop? The key to safety isn’t a louder engine or a faster wake; it’s reading the rules and the signals those rules rely on. In the ColRegs world, that means understanding who yields in a crossing and what the lights are telling you. Let’s break it down in simple terms.

The quick takeaway: who gives way in a crossing?

When two vessels are crossing paths, the vessel that sees a red light is the give-way vessel. In plain language: if you detect the other boat’s red light, you’re the one who should adjust course or slow down. The vessel that you’re looking at, which has a green light on its starboard side, maintains its course and speed. That green-signaled vessel has the right of way in this particular scenario.

You might be thinking, “But isn’t it about being the bigger boat or who’s on the starboard anyway?” That’s a fair question. Size can influence maneuverability, but in a crossing situation, the decisive factor the COLREGs emphasize is eye contact and light color. The red light is a cue that you’re on the other vessel’s port side; the other boat, with its green light on its starboard side, is the stand-on vessel in this crossing. Here’s the thing: the whole point of this signaling is to prevent a collision before it happens. Clear signals plus steady seamanship equals safer waters for everyone.

What the lights actually communicate

Let me explain what those colors and positions mean, because it’s easy to misread them in a hurry.

• Red light: This marks the port side (left side) of a vessel. If you see red ahead, you’re in a position where the other boat’s port side is directed toward you.

• Green light: This marks the starboard side (right side) of a vessel. If you can spot a green light, the boat presenting that light has its starboard toward you.

• White light: There are also white stern lights and other white navigation lights that help you determine direction, size, and movement, especially at night.

In a crossing scenario, when you notice the other ship’s red light, the rule says you should recognize that you are the give-way vessel. The other vessel—the one showing its green light on the starboard side—should keep its course and speed. It’s a bit of a mental flip from what you might assume if you only think “bigger ship has the right of way.” The COLREGs emphasize predictability and early action; the bright red light is a cue to begin yielding.

A quick mental model you can carry on deck

Here’s a simple way to remember it, without overthinking the details:

• If you see red, you’re the give-way vessel in a crossing with the other boat on its starboard side.

• The other boat with the green light keeps going, so you adjust your course or slow down to avoid a collision.

• If there’s doubt, reduce speed and communicate your intentions with sound signals or radio when appropriate.

This approach keeps the situation calm and workable, even when visibility is less than perfect or the water is choppy.

Why this rule exists (and why it matters)

Safety on the water often hinges on one thing: predictability. If two vessels both think the other should move, you’ve got a recipe for a collision. The red/green signaling creates a quick, unambiguous cue for who should act first, even if the two boats are moving at different speeds or in slightly different directions.

Think of it like driving at an intersection with a roundabout. If you know who has the right of way and you communicate clearly, you’re less likely to surprise the other driver. On the water, that communication comes from the navigation lights, a steady course, and a deliberate, early adjustment when signals indicate you should yield.

A note on other crossing scenarios

A lot of people ask about other cases, like when a large vessel and a small one cross, or when fog reduces visibility. The same principle—read the signals, act decisively, and maintain a safe speed—still applies. The size of a vessel is more about maneuverability and stopping distance than about who must yield in a crossing under standard conditions. And if you’re overtaking another vessel, different rules apply: the overtaking boat must keep clear and pass on the appropriate side, regardless of the other vessel’s lights. It’s a separate rule-set, but it reinforces the same overarching goal: avoid misunderstandings and collisions.

A few practical tips for real-world navigation

• Scan early for navigation lights, especially at dawn, dusk, or in fog. A quick glance can tell you whether you’re the give-way vessel or the stand-on vessel.

• Use your rule-of-thumb in rough water: if you’re uncertain about the other boat’s intentions, slow down and give more room. A little extra space now saves a lot of trouble later.

• Communicate when needed. A short blast of sound or a radio call can clear up mixed signals in poor visibility. Just remember the standard meanings of those signals and keep it simple.

• Don’t rely on size or speed alone. A big, fast boat can be constrained by conditions, and a small, nimble vessel might do something unexpected. Lights are there to keep things predictable for everyone.

• Practice with your crew. Short drills about responding to red lights or to a vessel showing a green light can make real-life decisions faster and safer.

A few everyday analogies to make it stick

Crossing rules aren’t about favoring one type of boat over another; they’re about shared courtesy in a crowded waterway. It’s a little like two cyclists meeting at a narrow path. If one cyclist signals that they’re going to slow down or let the other pass, the moment stays smooth and safe. The lights in the COLREGs work the same way, just with a few more color cues and a longer history of codified rules.

Putting it all together

So, when you’re asked to identify the give-way vessel in a crossing, remember the red light rule: the boat that sees a red light is the give-way vessel. The other boat, showing a green light on its starboard side, keeps its course and speed. It’s a precise, rule-based approach that reduces uncertainty and helps everyone stay in safe waters.

If you’re new to this world, that green-on-starboard cue can feel a bit abstract at first. Don’t worry. With time, you’ll start spotting reds and greens in your peripheral vision as you scan the horizon and keep one eye on the radar and the other on the water around you. And when you’re ready, you’ll notice how second nature it becomes to respond calmly, methodically, and safely.

A closing thought

The rules of the road at sea aren’t quaint relics from a dusty manual. They’re living guidelines that keep sailors and motorboats from colliding, even when traffic gets thick and visibility falters. The red-light gives-way principle is a reminder to stay deliberate, communicate clearly, and act with purpose. It’s not glamorous, but it’s powerful—and it works, coast to coast and across every kind of vessel.

If you ever want to talk through more scenarios—the crossing of a tall ship, the approach of a small fishing skiff, or how to interpret a late-night light pattern—let’s hash it out. After all, the water rewards clarity and calm judgment more than bravado or bravura. And with that, smooth sailing awaits.