Stand-on vessels must maintain course and speed when a risk of collision exists.

The moment you spot another vessel on a possible collision course, there’s a straightforward rule that keeps conversations clear and vessels safe: the stand-on vessel should maintain its course and speed. It sounds almost too simple, but this principle is the backbone of safe navigation at sea. Let me explain why it matters and how it plays out in real life on deck.

The heartbeat of predictability

Think about driving in fog on a winding road. If one driver suddenly swerves or slams on the brakes, the other person has to guess what’s coming next. Chaos. The same idea holds on the water, just with a different set of sensations—swell, wind, and the hum of distant machinery. When the stand-on vessel maintains course and speed, it provides a steady signal: “I’m not making a sudden move; I’m here and I’m watching.” That predictability is what lets the other vessel, the give-way vessel, evaluate the situation and decide the safest way to avoid a collision.

What the stand-on vessel does—and doesn’t do

Here’s the practical picture. The stand-on vessel stays on its established path and keeps its current speed. That’s the core obligation. It doesn’t mean ignoring danger or pretending nothing’s happening. It means you don’t start leaping into maneuvers that could confuse or surprise the other boat, especially if the other vessel hasn’t yet made a move to avoid a crash.

In the meantime, the stand-on vessel should:

• Keep a sharp lookout. Use all the tools at hand—radar, AIS, binoculars, and good old-fashioned watchkeeping. In busy waters, information is a weapon in your favor.

• Monitor the other vessel’s behavior. Watch for changes in relative bearing, speed, or course. If the other boat shows clear signs of not taking action, you’ll be ready to adapt—safely.

• Stay ready to act if needed. If the give-way vessel fails to take appropriate action, the stand-on vessel is allowed to take steps to ensure safety. But the initial move is not to poke at the other boat with abrupt changes; it’s to maintain that steady course while preparing to adjust if the situation deteriorates.

Why not change course or slow down right away?

That question comes up a lot because it feels natural to react fast when two boats seem destined to collide. Yet the rule is about clarity and order, not reflex. Changing course immediately or slowing down drastically can set off a chain reaction of sudden moves, which makes it harder for the other vessel to interpret intentions. In a crowded harbor or busy sea lanes, a rapid turn can mislead the give-way vessel about your real plan, or worse, invite misinterpretation from nearby traffic.

This is where disciplined seamanship shines. By holding your line, you’re reducing the risk of miscommunication. You’re saying, in effect, “I’m here, I’m steady, I’m not trying to play catch-up with you.” That steadiness buys time for everyone to sort out the best path forward.

The give-way vessel’s role—and why it matters

If you’re the stand-on boat, you’re not off the hook for staying alert. But the other side of the coin is the give-way vessel’s responsibility to take action to avoid a collision. The give-way vessel should slow, steer, or take other appropriate action to avert danger, using clear, predictable maneuvers. It’s a two-person dance: one boat remains predictable, the other boat adjusts. When both sides do their parts with calm, the risk of a mishap drops dramatically.

If the give-way vessel applies a change that would force you to break your course, then you have to reassess. The COLREGs allow you to take action if necessary to prevent a collision, but you do so with restraint and clarity, not with a rush or a sudden, jarring maneuver.

Real-world flavors: from calm lake to crowded harbor

The principle isn’t a one-size-fits-all rule—it adapts to what you’re sailing in and with whom you share the water. On a small sailboat skimming along a quiet lake, keeping your line steady can be straightforward. On a freighter crossing a busy shipping lane, your awareness and the other vessel’s behavior come with extra layers of complexity. In tight harbor channels, where the traffic pattern is dense and the momentum of larger ships can be measured in dozens of meters per second, the stand-on rule remains a touchstone for safety—but you’ll also lean more on sensors, radio chatter, and disciplined maneuvering.

And what about the not-so-obvious cases? Imagine two vessels with similar speed and bearing, or a vessel under sail and another powered craft. The same idea applies: maintain your course and speed unless the situation clearly demands you to shift gears. The moment you see uncertainty growing—like bearing tightening from the starboard or a sudden change in wind direction—you keep your options open. You’re staying ready to take action if the give-way vessel isn’t doing enough to avoid danger.

A quick checklist you can carry aboard

• Stay on course and maintain speed unless you’ve got a clear, necessary reason to alter your plan.

• Keep a vigilant lookout with all available tools (watch, radar, AIS, VHF) and interpret what they’re telling you about the other vessel’s path.

• Communicate through the proper channels and signals, so your intentions aren’t misread. Clear, predictable actions matter as much as the maneuvers themselves.

• If the other vessel appears not to act, be prepared to take steps to avoid a collision, but do so calmly and with consideration for nearby traffic.

• Remember that stopping the boat or making a dramatic turn right away can cause confusion, especially if the give-way vessel is not yet sure what you intend.

A few common misreads—and how to avoid them

Misreads are the stuff of near-misses. Some crews, especially those newer to the water, mistake a stand-on vessel’s steadiness for stubbornness. It’s not about stubbornness; it’s about clarity. Others worry that staying the course will leave them stranded if the other boat doesn’t move. But the rule is designed to create predictability, not capture you in place. The stand-on vessel isn’t frozen; it remains ready to adapt if the situation calls for it.

Another trap is chasing a moving target. If you chase the give-way vessel by darting side-to-side or changing speed in an abrupt, uncoordinated way, you’re inviting misinterpretation. The aim is steady, deliberate action, not theatrical improvisation.

A few words on equipment and culture

Modern ships carry a suite of tools—radar, AIS, GPS, autopilots, VHF radios—that help crews read the maritime environment with greater confidence. The best outcomes come from combining those technologies with solid seamanship: a disciplined watch, good team communication, and a shared understanding of how to respond when risk grows.

Even small boats can benefit from this mindset. A handheld VHF, a reliable chart plotter, and a practiced lookout become your safety net. The value isn’t in fancy gadgets alone; it’s about how you interpret information, how you communicate intent, and how you keep expectations clear among everyone on the water.

Putting it into plain language you can carry forward

Here’s the crisp takeaway: if there’s a risk of collision, the stand-on vessel should maintain course and speed. That single rule helps everyone stay on the same page, reduces surprises, and gives the other vessel space to act. If the other boat doesn’t respond adequately, you’re allowed to take steps to avoid danger. But the initial, guiding action is steady: stay where you are, keep watching, and be ready to adapt—calmly, deliberately, and safely.

The water has its own rhythm, and the rule of staying on course respects that rhythm. It’s not about stubbornness or rigidity; it’s about making the water safer for everyone who shares it. When you’re out there, that straightforward approach can be more powerful than a flurry of late, hurried moves.

A closing thought

The world of navigation is a blend of science and instinct. The rule to maintain course and speed when a collision risk exists isn’t just a rule—it’s a habit you cultivate. It helps you read the sea more clearly, it keeps your crew aligned, and it gives you one less thing to doubt when the weather turns a little uncertain. So next time you’re at the helm and another vessel appears on the radar, remember the steady path. It’s a simple command, but it carries the weight of safety, clarity, and shared purpose on every voyage.