Rule 15 Explained: The give-way vessel must take early and substantial action to keep clear.

Rule 15: When to yield and how to do it right

Let me ask you a quick question. When two boats are on a collision course, who should change course first? If you said the give-way vessel, you’re catching the spirit of Rule 15. This rule is all about who yields, how quickly, and why it matters more than who has the right of way. If you’re out on the water, every second counts, and the right move is to act early and decisively to keep clear.

What Rule 15 really says

Here’s the thing: the give-way vessel is the one that must take active steps to avoid a collision with the stand-on vessel. It’s not about making a big show or shouting out intentions from a distance—it’s about tangible action. The aim is simple and practical: alter your path or slow down so the other vessel can carry on without having to make abrupt, last-minute changes.

Why the “early and substantial” part matters isn’t just a nicety. If you wait, the options become limited. You might have to make a sudden turn or a sudden stop, which increases the risk of collision and can surprise the stand-on vessel. The idea is to give the other boat safety margins by removing the most dangerous possibilities early.

What the other choices suggest—and why they miss the mark

• Maintain course and speed (B): It sounds diplomatic, but it’s the exact opposite of what Rule 15 requires. If you’re the give-way vessel, holding your course and speed can force the stand-on vessel to adjust, which defeats the purpose of the rule and raises the chance of a close call.

• Change direction abruptly (C): Abrupt movements are the fastest way to surprise the other boat and induce a hazardous situation. Quick, sharp turns aren’t just uncomfortable; they’re dangerous on the water, where mass and momentum can turn a near-miss into a collision.

• Signal intentions to the stand-on vessel (D): Signaling is helpful, but it’s not a substitute for action. You can say “I’ll pass you on your port side” in a chorus of horn blasts, but unless you actually alter your course or slow down, you’re not satisfying the rule’s core duty to yield safely.

“Early and substantial action” in practice

Let’s break down what that phrase looks like in real terms. The moment you recognize a risk of collision, you should start adjusting well before things become tight. Here are the practical moves that embody Rule 15:

• Slow down gradually: Reducing speed buys time for both vessels to gauge the other’s intentions and slows the relative closure rate. It’s easier to maneuver when you’re not coming in hot.

• Alter course in a controlled way: A gentle, predictable turn away from the stand-on vessel—usually toward the side that increases the safety margin—is preferred. Sudden, sharp swings can confuse nearby traffic and magnify the risk.

• Communicate when needed: If the situation is unsettled, use clear signals to reduce ambiguity. Short, well-timed sound signals or radio communications (where appropriate and permitted) can help establish a shared understanding of each vessel’s actions.

• Don’t assume the stand-on vessel will automatically adjust: The stand-on boat is supposed to keep its course and speed, but you can’t rely on that. Give them a buffer by your own decisive maneuver.

• Leave room for the other vessel to respond: The goal isn’t to “win” the right of way; it’s to ensure safe passage. That means making room for the stand-on vessel to adapt without needing to perform abrupt maneuvers themselves.

A concrete scene you might picture

Imagine two boats crossing paths in a busy channel. The stand-on vessel is on a steady, predictable track. If the other boat—the give-way vessel—waits, the crossing becomes precarious. The give-way boat should act early: ease off not just a little, but enough to offer a clean pass. A slight turn to the right or left, a gentle deceleration, and clear, calm indication of your intended path can eliminate the tension. It’s about reading the water like a good driver reads traffic lights—seeing the risk early, responding calmly, and letting everyone keep moving.

What this means for your navigation mindset

Rule 15 isn’t about clever maneuvers or clever labels; it’s about safety-first habits that translate to better seamanship. When you’re navigating, you’ll encounter a spectrum of situations:

• Crossing situations: This is where Rule 15 plays a starring role. The give-way vessel must do what it takes to keep clear so the stand-on vessel can continue on its intended course without sudden upheaval.

• Overtaking and head-on encounters: These scenarios involve different rules, but the same underlying logic applies—predictability, space, and timely actions keep everyone safe.

• Limited visibility or congested waterways: In busy harbors or fog, early action isn’t just smart; it’s essential. The more crowded the water, the more you rely on clear, deliberate decisions.

A few practical reminders for sailors, anglers, and crew alike

• Identify the roles early: Before you get too close to another vessel, take stock of which boat is the stand-on and which is the give-way. It’s not always obvious at first glance, but you can infer it from positions, speeds, and headings.

• Keep a steady hand on the wheel: Smooth, predictable movements reduce the chance of confusing other traffic. Sudden course changes can escalate anxiety and risk.

• Use all available tools: Radar, AIS, and even good old-fashioned lookouts at the bow can help you see risk sooner. If you have VHF, don’t hesitate to communicate when there’s doubt about what the other boat plans.

• Don’t rely on luck: Waters aren’t forgiving. Treat every near-miss as a chance to sharpen your judgment and refine your response.

Remembering the core message

The essence of Rule 15 is simple in its intention, even if the waters you navigate are complex: the give-way vessel must take early and substantial action to keep clear of the stand-on vessel. It’s about safety, clarity, and making space for other boats to pass without drama. It’s not a fancy maneuver; it’s good seamanship in action.

Quick tips you can carry on deck

• Trust your eyes and your speed judgment. If something looks off, start adjusting sooner rather than later.

• Keep your actions observable. A gentle swing or a slow slowdown is easier for others to read than a sudden, abrupt move.

• Talk it out with your crew. A quick crew brief on who does what in crossing situations can prevent confusion.

• Practice in calm conditions. The more you rehearse orderly, deliberate responses, the more natural they feel when conditions aren’t ideal.

A little metaphor to seal the idea

Think of Rule 15 as a courteous dance between two boats. The give-way vessel leads with a careful step, one that creates enough space for the stand-on vessel to finish its move without stepping on toes. There’s a rhythm to it—a tempo of alertness and action—that keeps the water a safer place for everyone aboard.

Bringing it all together

If you’re ever unsure what to do in a near-miss situation, the best compass is this: act early, act decisively, and act to keep clear. The stand-on vessel should be able to continue its course with minimal adjustment, and the give-way vessel should provide that safety margin through timely changes in speed or direction. In the end, Rule 15 isn’t about who has the right to move first; it’s about ensuring that everyone aboard stays safe while they share the same waterway.

So next time you’re navigating through traffic or planning a crossing, ask yourself: have I taken early and substantial action to keep clear? If the answer is yes, you’re likely following Rule 15 the way it was meant to be followed—through steady hands, clear intention, and a respect for the shared space that the sea requires.