Have you ever felt that sudden, cold knot in your stomach when you realize you’re looking at a situation you aren't prepared for? Maybe you’re standing on a bridge, staring at a radar screen, and you realize the ship you're operating is being passed Took long enough..
It’s one of those moments where the silence in the wheelhouse feels a lot heavier than usual. You know the rules of the road, you’ve done the training, and you’ve passed your exams. But when a massive tanker or a fast-moving commercial vessel starts closing the distance on your flank, the theory meets the reality of moving tons of steel through water Practical, not theoretical..
It’s easy to stay calm when you’re reading a manual. It’s a lot harder when you're actually responsible for the safety of a crew and a cargo.
What Is Being Passed?
In plain English, being passed means another vessel is moving alongside you, usually in the same direction, but at a different speed. It sounds simple enough, right? Now, one ship is just overtaking another. But in the world of maritime navigation, "being passed" is a specific interaction that requires constant attention And that's really what it comes down to..
The Geometry of the Encounter
When a vessel is being passed, you aren't just watching a dot move on a screen. You're managing a complex geometric relationship between two moving objects. The passing vessel is typically moving faster than you, and they are approaching from your stern or your quarter Most people skip this — try not to. Worth knowing..
The real challenge isn't just knowing they are there. Worth adding: it’s predicting where they will be in ten minutes, twenty minutes, or an hour. You have to account for your own speed, their speed, the angle of their approach, and—this is the part that catches people off guard—the effect of currents and wind on both hulls That's the whole idea..
Some disagree here. Fair enough.
Overtaking vs. Passing
There’s a subtle but vital distinction here. In many contexts, people use these terms interchangeably, but they aren't the same. On top of that, an overtaking maneuver is a specific action where one vessel passes another by going ahead of it. If you are the vessel being passed, you are the "give-way" vessel in some scenarios, or the "stand-on" vessel in others, depending on the specific rules of the International Regulations for Preventing Collisions at Sea (COLREGs) Worth knowing..
Understanding which role you play is the difference between a smooth transit and a near-miss.
Why It Matters
Why do we spend so much time talking about this? Because when a vessel is being passed, the margin for error shrinks rapidly.
If you miscalculate the speed of the overtaking vessel, you might find yourself in a situation where they are much closer to your stern than you anticipated. Or, worse, they might be intending to pass ahead of you, but their trajectory is shifting toward your bow It's one of those things that adds up..
The Risk of Misinterpretation
The biggest danger isn't usually a lack of visibility. And it's a lack of communication—both between the two vessels and between the bridge team and the helmsman. If you assume the other vessel is going to pass astern (behind you) but they actually intend to pass ahead, you could find yourself in a crossing situation that you weren't prepared to manage Simple, but easy to overlook..
When things go wrong, they go wrong fast. A vessel passing at 15 knots doesn't need much time to close a gap. If you realize too late that the passing vessel is not maintaining a safe distance, your options for evasive action become extremely limited.
Real talk — this step gets skipped all the time.
The Psychological Toll
There's also the human element. Being passed by a much larger vessel can be intimidating. The sheer scale of a VLCC (Very Large Crude Carrier) looming in your blind spot creates a sense of pressure. That pressure can lead to "tunnel vision," where you focus so hard on the passing ship that you stop monitoring your own course, your depth, or other traffic in the vicinity.
How to Manage a Passing Vessel
So, how do you actually handle this without breaking a sweat? It starts with proactive observation. You don't wait for the ship to be right next to you to start thinking about it That's the whole idea..
Early Detection and Monitoring
The moment you see a target on the radar or a silhouette on the horizon that is closing the distance, your work begins. Relative Motion: Is the target's bearing constant? Speed Differential: How much faster are they going than you? In real terms, you need to determine three things immediately:
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- If the bearing is steady, they are on a collision course or passing directly astern.
- Consider this: if the bearing is changing, they are crossing your path. Intent: Based on their current heading and speed, what is their likely maneuver?
Using the Tools at Your Disposal
Modern bridge technology is incredible, but it's only as good as the person using it.
- ARPA (Automatic Radar Plotting Aid): This is your best friend. Use it to get accurate vectors. Don't just look at the symbol; look at the trend.
- AIS (Automatic Identification System): This gives you the "why" behind the "what." You can see the name of the vessel, its cargo, its destination, and its intended course. It takes the guesswork out of who they are and what they might do next.
- Visual Bearings: Never rely solely on electronics. If the weather allows, take a visual bearing. If the radar says one thing and your eyes say another, trust your eyes—but check the radar again.
Communication Protocols
If you are in a busy channel or a high-traffic area, don't be afraid to use the VHF radio. A simple, professional call can clear up a lot of confusion Simple, but easy to overlook..
"Vessel [Name], this is [Your Vessel Name]. We see you are passing our starboard quarter. Are you intending to pass astern?
It might feel redundant, but in a professional environment, clarity is always better than assumptions. It's better to be "that guy" who asks a question than the officer who makes a fatal assumption Simple as that..
Common Mistakes / What Most People Get Wrong
I've seen plenty of experienced mariners make mistakes during passing maneuvers. Usually, it’s not because they don't know the rules, but because they fall into one of these traps Simple as that..
The "Steady Bearing" Trap
A lot of people think that if the bearing of the passing vessel remains constant, you are safe. Day to day, they assume a steady bearing means they are passing behind you. But here's the thing—a steady bearing can also indicate a collision course if the vessels are on intersecting paths. You have to look at the range (distance) and the relative motion, not just the bearing.
Over-Reliance on AIS
I'll say it again: AIS is not a substitute for radar or visual observation. Day to day, aIS data can be wrong. It can be delayed. Also, it can be entered incorrectly by a tired officer on another bridge. Practically speaking, if the AIS says the ship is 2 miles away, but your radar shows them at 1. 5 miles, trust the radar.
The "Wait and See" Approach
This is the most dangerous habit. You see a vessel approaching, you see they are moving fast, and you think, "I'll wait until they are closer before I change course."
By the time you decide to act, you have lost your "maneuvering room.Day to day, " You are now forced to make a sudden, drastic change that might actually put you in more danger. The best time to make a small, subtle course change is long before it becomes a large, desperate one But it adds up..
Practical Tips / What Actually Works
If you want to handle passing maneuvers like a pro, you need to move from being reactive to being proactive. Here is what actually works in the real world Most people skip this — try not to..
The "Rule of Three" for Maneuvering
When you decide to take action, follow these three steps:
- Make it predictable. A small change in course or speed made early is much safer than a large, sudden movement made late. ** If you change course, make sure the other vessel can clearly see it on their radar and visually. Consider this: ** Don't zig-zag. **Make it early.A slight nudge might not be enough; a clear, decisive turn is better. That's why 3. **Make it obvious.Still, 2. Don't make sudden, erratic movements that leave the other captain guessing.
Standardize Your Bridge Team Meetings
If you have a lookout or a second officer on duty, don'
Advanced Communication Protocols
Effective communication goes beyond a brief meeting; it becomes a continuous dialogue throughout the maneuver. Encourage every team member to adopt a “watch‑and‑report” mindset. The lookout should call out any change in the target’s radar plot or visual aspect, while the officer of the watch (OOW) confirms the information on the ship’s own sensors before issuing further instructions. Even so, use a concise, standardized phraseology—such as “Target confirmed, 2 nautical miles bearing 270°”—to reduce ambiguity. But when a course alteration is ordered, the helmsman should acknowledge the command with a clear “ helm to port/starboard, maintain speed” and the OOW should repeat the intended effect (“Turning to 180°, speed 12 knots, proceeding on intended track”). This closed‑loop process ensures that no single point of failure can slip through unnoticed.
Real talk — this step gets skipped all the time.
Sound Signals and Light Signals as Backup
Even with perfect electronic monitoring, there are moments when the bridge must rely on traditional methods. When a vessel’s AIS data is delayed or appears unreliable, the standardized sound signal sequence—single prolonged blast for “I am altering my course to starboard,” two short blasts for “I am altering my course to port,” and three short blasts for “I am operating astern propulsion”—provides an unambiguous warning. Complement these with appropriate navigation lights; ensure the ship’s own lights are correctly displayed and that the crew can quickly verify the other vessel’s lights against the International Regulations for Preventing Collisions at Sea (COLREGs). In low‑visibility conditions, a brief flare or a handheld strobe can serve as a visual cue that the maneuver is underway No workaround needed..
Quick note before moving on Not complicated — just consistent..
Real‑World Scenario Checklist
- Pre‑maneuver verification – Cross‑check AIS, radar, and visual observations; confirm the target
Real‑World Scenario Checklist (continued)
- Pre‑maneuver verification – Cross‑check AIS, radar, and visual observations; confirm the target’s CPA/TCPA, aspect, and true course. Verify that your own vessel’s data (speed, heading, destination) is accurately broadcasting on AIS.
- Risk assessment – Classify the encounter (head‑on, crossing, overtaking) per COLREGs Rule 14–15. Determine if a “stand‑on” or “give‑way” obligation exists and whether the other vessel appears to be taking appropriate action.
- Decision window – Establish a hard deadline (e.g., “Action required by 0.5 NM CPA”) so the team knows exactly when indecision becomes a hazard.
- Execution – Apply the Rule of Three: early, obvious, predictable. Log the ordered helm and engine movements in the bridge movement book.
- Post‑maneuver monitoring – Maintain increased vigilance until the target is clear astern or well clear on the beam. Re‑acquire the target on radar/visual to confirm separation is increasing.
- Debrief – Within 30 minutes, conduct a brief bridge team review: What worked? What was ambiguous? Update the passage plan or standing orders if a systemic gap is identified.
Integrating Technology Without Over‑Reliance
Modern bridge suites—ARPA, ECDIS overlay, AIS CPA/TCPA alarms, and predictive collision‑avoidance software—are powerful force multipliers, but they are decision‑support tools, not decision‑makers. Now, treat every electronic output as a hypothesis to be validated by the human eye and independent sensors. A radar track can be lost in sea clutter; an AIS target can be spoofed or stale; an ECDIS safety contour can be mis‑set. Because of that, build “sensor fusion” into the watch routine: the OOW should mentally overlay radar, AIS, visual, and sound inputs before committing to a maneuver. If any single source disagrees with the others, assume the worst‑case geometry and act conservatively Worth knowing..
And yeah — that's actually more nuanced than it sounds Simple, but easy to overlook..
Fatigue, Complacency, and the Human Factor
Even the best procedures collapse when the bridge team is fatigued or complacent. Use the “challenge‑and‑response” technique during quiet watches: the OOW asks the lookout, “What is the closest target and its trend?Rotate lookout duties every 30–60 minutes in high‑traffic areas to keep visual scanning sharp. Enforce the STCW rest‑hour requirements rigorously, but also recognize that “legal rest” does not guarantee alertness. But ” forcing active engagement. Encourage a culture where questioning a senior officer’s maneuver is seen as professional diligence, not insubordination—this is the essence of Bridge Resource Management (BRM) That's the part that actually makes a difference..
Legal and Insurance Implications
A well‑documented, early, and obvious maneuver is your strongest defense in any subsequent inquiry or claim. In practice, the bridge movement book, VDR/VDR‑S data, and the OOW’s narrative log must tell a consistent story: risk identified, COLREGs rule applied, action taken early and communicated clearly. Inconsistent entries—e.Plus, g. Worth adding: , a course change logged at 02:14 but the VDR showing 02:18—create liability exposure. Train officers to treat every log entry as potential evidence The details matter here..
Not the most exciting part, but easily the most useful.
Conclusion
Collision avoidance is not a single moment of heroics; it is a disciplined, repeatable process that begins long before two vessels reach the “critical distance.The Rule of Three—early, obvious, predictable—remains the golden thread linking every decision on the bridge. When each officer, lookout, and helmsman internalizes that thread, the ship doesn’t just avoid collisions; it navigates with the quiet confidence that comes from professional mastery. ” By standardizing bridge team meetings, closing the communication loop, backing electronic aids with sound and light signals, and embedding a concise real‑world checklist into daily watchstanding, you turn the chaotic geometry of a close‑quarters encounter into a controlled, predictable evolution. Safe passages are not a matter of luck—they are the product of a culture that plans early, communicates clearly, and executes decisively, every single watch Which is the point..
