What the '_ _ . OR .' signal means for overtaking on the starboard side under COLREGs.

What the Starboard Overtaking Signal Really Means Under COLREGs

If you’ve ever been at sea or watched ships glide past in a busy harbor, you know that clear communication is as essential as a steady hand on the wheel. A ship can’t rely on bright lights or horns alone to keep everyone safe; it also relies on standardized signals that tell other vessels what to expect. One of the most important of these signals is the overtaking warning. Specifically, a particular sound pattern—one prolonged blast followed by one short blast—tunches into a captain’s mind with a clear message: I intend to overtake you on my starboard (right) side. Let me unpack what that means, why it matters, and how to respond when you hear it.

The kind of signal that matters

In the world of COLREGs—the International Regulations for Preventing Collisions at Sea—the communication system is designed to be precise, intuitive, and universal. It’s a bit like traffic signals on a coastal map. When two vessels are moving in ways that could bring them into contact, they use a set of whistle sounds to spell out their intentions. The starboard overtaking signal — the one long blast followed by one short blast — is a specific, deliberate way for the overtaking vessel to say, “I will pass you on your right.” If you’re the vessel being overtaken, you hear that sequence and you know the overtaking vessel will stay on the starboard side as it moves past.

Contrast that with other sound signals you’ll encounter in busy waters. There are signals to indicate a vessel’s intention to pass on the port side, and there are signals that alert others to danger, to changes in course, or to stops and starts. The key is to recognize that each pattern has a precise meaning, and misinterpreting them can lead to a bad spill of confidence—and possibly a collision.

Why this matters in real life

Think of standing at a junction with a fog bank rolling in. Cars have turn signals; ships have whistle signals. The system isn’t there to complicate things; it’s there to reduce risk. The starboard overtaking signal is a proactive step in that safety chain: it lets nearby vessels anticipate where a ship will be and how it will move. When you’re at the helm, understanding this single signal can save minutes—and in rough seas, minutes matter a lot.

The signal’s logic is simple in principle, but the seas aren’t always friendly. Visibility can be limited by fog, rain, or spray. A radio on channel 16 might offer confirmation or a quick exchange, but the whistle signal remains a primary, universal cue. If you know what to listen for, you won’t have to rely on luck or guesswork. And that’s the essence of COLREGs: a shared language for navigators to prevent collisions.

What to do when you hear it

If you hear the starboard overtaking signal (one prolonged blast, then one short blast), here are practical steps to keep things smooth and safe:

• Stay alert and assess: The overtaking vessel is planning to go past your starboard side. Give your full attention to your intended path of motion, the other vessel’s speed, and any traffic nearby.

• Maintain or adjust speed as needed: The stand-on vessel should generally keep its course and speed, but it can adjust if staying clear becomes unsafe. If you suspect the overtaking vessel will close the gap too quickly, you may ease your speed a bit to create a safe passing distance. Do not speed up abruptly to “beat” another vessel; that can create a dangerous situation.

• Keep a steady course and watch the approach: Vigilance matters. Keep your eyes on the overtaking ship, its wake, and any nearby boats. Use radar or AIS if you have them to confirm the other vessel’s movements.

• Communicate clearly if needed: If there’s any doubt about the intended path or if visibility is poor, use VHF radio to communicate with the other vessel. A quick, polite exchange can prevent missteps. Remember to switch to the appropriate channel when you’re done.

• Don’t get distracted: A single signal can be followed by rapid changes in speed or direction from either vessel. Stay focused on the overall picture and your own boat’s safety envelope.

• Follow through with a safe passing plan: As the overtaking vessel completes its maneuver, both boats should stay clear. The overtaker should ensure safe clearance and then proceed smoothly.

A quick scenario to anchor the idea

Imagine you’re piloting a small coastal tug on a busy stretch near a port. A larger freighter is behind you and begins to signal with the starboard overtaking call. You don’t swing your wheel wildly or slam on the brakes. You maintain your course, monitor the approach, and perhaps adjust slightly to create a clearer channel. The freighter, recognizing that you haven’t altered course abruptly, glides by on the starboard side with a comfortable margin. There’s no shouting, only a mutual understanding: we’ve shared a signal, and now we pass safely. If either party forgot the signal’s meaning, the result could be a tense moment or worse.

Common muddles worth clearing up

• Starboard versus port: Starboard is the right side of a vessel when you face forward. Port is the left. It’s not a vague guess; it’s a standard reference point used in all official instructions and by captains everywhere.

• Signals aren’t “permission”: They’re intentions and a cue for action. The overtaking signal doesn’t automatically give one vessel permission to speed up or slow down; both vessels need to manage their own responses to keep safe clearance.

• Signals can be complemented by additional communications: In poor visibility, a radio check or a brief exchange on VHF can help cement mutual understanding. Tools and technology aren’t replacements for sound signaling; they’re supplements that reduce ambiguity.

• Remember, context matters: A starboard overtaking signal might be part of a wider set of operational signals in a busy channel. The same sequence could appear in conjunction with altered courses or speed changes from others nearby.

Memorization tips that actually help

If you want to classify this in your mind without turning it into a memory maze, think of two core ideas:

• The starboard overtaking signal = long blast + short blast. It means, “I intend to pass you on my right.”

• Overtaking is a proactive maneuver: It requires both vessels to anticipate and adjust, but the primary responsibility rests on the overtaking vessel to navigate safely.

A few memorable analogies

• It’s like a car’s right-side pass signal during a high-traffic roadway, but with sound instead of blinkers.

• Picture a synchronized dance on a crowded stage: one dancer signals intention, the other keeps a steady rhythm to allow safe passage. Communication keeps the performance safe and graceful.

• When you hear that starboard sequence, think, “Right side, I’m passing.” It’s a cue rather than a command, a cue to stay patient and give space.

Practical takeaways for the curious navigator

• Know the rules, then watch for the cues: The starboard overtaking signal is a fundamental cue in the COLREGs toolbox. It’s easy to misread in the heat of the moment, so practice listening for that exact pattern and interpreting it quickly.

• Create a mental checklist for encounters: Lookout, speed, heading, and signaling patterns. A quick mental checklist can transform a tense moment into a controlled maneuver.

• Use resources to reinforce learning: Official guidelines, maritime training videos, and reputable nautical training platforms can reinforce what you’ve learned. Charts, radar displays, and AIS can all support your understanding of who’s where and what’s likely to happen next.

• Don’t rely on luck: The sea is unpredictable. Signaling is a systematic approach to reduce uncertainty, not a guess. Respect the signals, and ensure you always have a clear plan to stay safe.

A closing thought

The starboard overtaking signal is one of those small-but-crucial elements that reveals how much order underpins the sea’s chaos. It’s a reminder that even on a rolling ocean, communication remains our strongest tool. As you continue to explore the Rules of the Road, remember that every sound, every signal, every directive has a purpose: to keep us, and every other mariner, moving safely toward shared destinations.

If you’re curious to dig deeper, look into Rule 34 of COLREGs and its companion provisions around overtaking. You’ll notice the intent is not to complicate the voyage but to offer a clear, predictable framework for action. And in the end, clear signals + calm, deliberate responses are what turn potential hazards into manageable situations—and that’s the heart of good seamanship.