Rule 13 explained: when another vessel is on your starboard side, you must keep out of the way.

Rule 13 in the COLREGs: Who Yields When Two Sailing Vessels Meet

Two boats on a sunny day, a seam of spray, and a moment where the right-of-way decisions really matter. That moment is what Rule 13 is all about. If you’ve ever found yourself trying to read the behavior of another vessel at an angle, you’re not alone. The rule is straightforward in plain terms, but applying it on the water—in wind, chop, and changing light—makes all the difference between a safe crossing and a tense near-miss.

Here’s the heart of Rule 13, in simple words: when two sailing vessels are approaching each other in such a way that they might collide, the vessel that has the other on its starboard side must keep out of the way. In practical talk, that means the boat on the other vessel’s right-hand side has the right of way. The other boat must yield, adjust course, or slow down to let the starboard-side vessel pass safely.

Let me explain why this matters. On a busy stretch of water, you’ll frequently see boats crossing paths at slight angles. One boat appears to be to your right; the other seems to be on your left. Who goes first? If you have the other boat on your starboard side, you are the “stand-on” vessel. You should hold your course and speed. The other boat—the give-way vessel—must maneuver so the two boats don’t collide. It’s a cooperative rule, built to reduce surprise moves and keep everyone clear.

Common misreads to clear up

• A. The wind direction on its port side? No. That matters for sails and how you set your course, but Rule 13 is about the relative position of the other vessel, not wind orientation. It’s easy to mix this up because sailors constantly think about wind, but the starboard rule is the key focus here.

• C. The larger draft? Not a factor in this rule. Draft is more about depth and clearance under the waterline, not who must yield in a crossing of two sailing vessels.

• D. The faster vessel? Speed can influence how you execute a maneuver, but the rule says nothing about who must yield based on speed. It’s about the right-of-way defined by the other vessel’s position.

The practical takeaway is simple: identify which boat has the other on its starboard side. That boat must do the yielding. If you’re the starboard-side vessel, you’re the one with the right of way; keep your course and expect the other boat to adjust if needed. If you’re the vessel with the other boat on your starboard, you should alter course to pass safely, giving the starboard vessel room to move without forcing a risky change or sudden stop.

A quick, real-world example

Imagine you’re sailing close-hauled in a light breeze, and another vessel appears on your starboard side. You’re the stand-on vessel. You maintain your current course; you don’t speed up to try to outrun, and you don’t veer suddenly unless the other vessel doesn’t take the hint. At the same time, the other boat, seeing you on its starboard side, should begin to adjust—usually by turning slightly to port (to the left) and ensuring there’s enough space between you to avoid a collision. It’s a give-and-take dance, done with small, predictable moves rather than dramatic shifts.

Why this rule exists

Collision avoidance on the water isn’t a free-for-all. Rules like Rule 13 create a predictable framework so two vessels can see and anticipate each other’s moves. The starboard rule reduces confusion in crossings and makes decisions quick and consistent. It’s not about who is bigger, faster, or heavier; it’s about who has the right of way in a crossing scenario and who must yield to keep everyone safe.

What to watch for in the moment

• Early visibility: As you approach a crossing, keep a lookout for any vessel that might come onto your starboard side. The moment you spot one, you can begin planning your response.

• Clear, early action: If you’re the give-way vessel, start your maneuver early. A small course change to the left or right, well before you’re too close, is much safer than a late, abrupt move.

• Maintain room to maneuver: Avoid tilting the balance with sudden speed changes or sharp turns. The goal is a smooth, predictable adjustment.

• Communication: With horns or light signals (as appropriate), indicate your intention if there’s any doubt about intent. Clear signaling reduces surprises for the other crew.

• Mixed traffic scenarios: When power-driven vessels mix with sailing vessels, other rules (like Rule 18 for power-driven vessels or Rule 17 for stand-on and give-way interactions) come into play. In a crossing with sailing vessels, the starboard-right principle still guides the initial expectation, but be ready to adapt if another rule applies.

A few thoughts on the bigger picture

Rule 13 sits alongside a whole family of rules about crossing, meeting head-on, and near-miss situations. You’ll hear about stand-on vessels and give-way vessels, and you’ll learn that sometimes speed and maneuverability change the practical outcome. The sea doesn’t come with a whiteboard; decisions happen in real time, under pressure, with the wind and waves as unpredictable teammates. The more you internalize this starboard rule, the quicker you’ll recognize what to do—and what not to do.

A small digression that actually matters

If you’ve ever driven a car, think of Rule 13 a bit like turning onto a busy cross street. At an intersection with two cars approaching from different directions, the one on the right usually has the priority, unless there are traffic signs that say otherwise. On the water, the logic is similar, but the field of play is more fluid. You don’t have traffic lights; you have the wind, the other boat’s position, and a shared commitment to safe navigation. The rule is a reminder that, in a shared space, clarity and courtesy keep everyone moving forward.

Putting it all together

• The core idea: When two sailing vessels meet, the vessel with the other on its starboard side must keep out of the way.

• The stand-on vessel is the one that has the other on its port side; it should maintain course and speed.

• The give-way vessel—whose starboard-side counterpart lies on its own starboard side—must adjust to prevent a collision.

• The wind, draft, or speed by themselves don’t decide who yields in Rule 13; the relative position does.

A final perspective

Rule 13 isn’t a morality tale; it’s a practical tool. It’s a simple rule that helps boats act like a well-rehearsed team even when the water is a little rough or the breeze changes. If you can quickly determine who has the other on their starboard side, you’re already halfway to a safe crossing. And honestly, that quick assessment—done early and done calmly—can be the difference between a smooth voyage and a tense moment at sea.

If you ever find yourself thinking about this rule while daydreaming at the helm, you’re not alone. The sea rewards clear thinking and steady hands. Rule 13 is one of those little anchors that keeps navigation sane: respect the right of way, expect a yield, and always keep safety front and center.

In sum: when two sailing vessels meet at an angle, the vessel that has the other on its starboard side must keep out of the way. The starboard vessel has the right of way; the other must adjust. That’s the essence, clean and simple, and it’s the kind of principle that makes real-world seamanship feel a bit more like music—predictable, coordinated, and safe.