Collision Avoidance for Sailing Vessels 

Collision Avoidance for Sailing Vessels. Most sailing articles about collision avoidance focus on the collision regulations. Those rules are important and every skipper should understand them thoroughly. However, after many years of sailing, I have come to believe that successful collision avoidance has far less to do with knowing the rules and far more to do with recognising developing situations early. By the time the regulations become important, a skipper should already have been assessing the risk for quite some time.

My earliest lessons in collision avoidance came from racing dinghies rather than cruising yachts. In a racing fleet, boats are constantly converging, crossing and manoeuvring in close proximity. You quickly learn that knowing where another boat is matters far less than understanding where it will be in the future. The same lesson has remained valuable aboard my boat La Jonquille. Whether the other vessel is a yacht, fishing boat or commercial ship, collision avoidance begins with anticipation rather than reaction.

Collision Avoidance for Sailing Vessels - Collision Risk Usually Develops Slowly

One of the most reassuring truths about collision avoidance is that genuine collision risks rarely appear suddenly. In most situations, the clues are available long before a close-quarters situation develops. The challenge is maintaining a lookout that is good enough to recognise those clues while there is still plenty of time to act.

Many incidents occur not because another vessel was invisible, but because it was observed without being properly assessed. A skipper sees a target, mentally notes its presence and then moves on to something else without considering whether the situation is actually changing. Effective collision avoidance begins when the skipper moves beyond simply identifying traffic and starts evaluating what that traffic is doing.

Collision Avoidance for Sailing Vessels - Practical Example

During coastal passages aboard La Jonquille, I often notice vessels many miles away long before they become operationally significant. Most eventually pass without requiring any action at all. The important point is that I already know they exist. By the time a vessel becomes relevant, I already have a picture of how the situation has been developing rather than trying to assess it from scratch.

The Most Important Question Is Whether the Bearing Is Changing

Of all the collision-avoidance principles I have learned over the years, none has proven more useful than understanding relative bearing. A vessel that remains on a constant bearing while the range continues decreasing should immediately attract attention. It does not guarantee a collision risk, but it is one of the clearest indicators that further assessment is required.

This is not a concept I learned from a textbook. Dinghy racing teaches it naturally. Sailors quickly become aware of whether a competitor is moving ahead, falling behind or remaining in roughly the same position. Without formalising it, you start thinking in terms of relative movement. Offshore sailing uses exactly the same skill, simply over greater distances and timescales.

Collision Avoidance for Sailing Vessels - Practical Example

One habit I developed aboard La Jonquille is occasionally checking whether another vessel appears to be moving against background features such as clouds, coastlines or the horizon. If the bearing remains remarkably stable over time, I immediately become more interested in the situation. More often than not, further observation confirms there is no issue, but it is frequently the first clue that deserves attention.

Collision Avoidance for Sailing Vessels - Looking Is Not the Same as Seeing

I have sometimes heard sailors describe collision avoidance as maintaining a good lookout. While technically correct, I think it misses an important point. Looking is not the same as seeing. A person can spend hours staring out of a cockpit while absorbing surprisingly little information.

Good lookout practice is an active and proactive process. It involves continuously searching for developing situations, evaluating movement and reassessing previous observations. This is one reason fatigue can have such a strong influence on collision avoidance. A tired watchkeeper often continues looking in the right direction while becoming less effective at interpreting what they see.

Collision Avoidance for Sailing Vessels - Practical Example

During one overnight passage aboard La Jonquille, a vessel was identified visually well before it became significant. What interested me was not the sighting itself but how its behaviour developed over time. By occasionally revisiting the target and reassessing its movement, it became clear that what initially appeared unremarkable deserved greater attention. The vessel never became a threat, but the exercise reinforced an important lesson. The value of a lookout lies in interpretation, not observation alone.

Collision Avoidance for Sailing Vessels - AIS Is a Tool, Not a Lookout

AIS has become one of the most valuable collision-avoidance tools available to cruising sailors. I would not want to undertake regular offshore passages without it now that I have it aboard. It provides information that previous generations of sailors simply did not have, particularly when assessing commercial traffic beyond visual range.

However, AIS is often misunderstood. It is not a substitute for a lookout and it should never become the primary source of awareness. Not every vessel carries AIS and not every AIS target provides a complete picture of the developing situation. Good situational awareness still begins outside the boat rather than on a screen.

Collision Avoidance for Sailing Vessels - Practical Example

Aboard La Jonquille, I generally treat AIS as a way of confirming observations rather than replacing them. When I identify a vessel visually, AIS often helps clarify its speed, course and closest point of approach. Equally, AIS may alert me to traffic beyond visual range. In both situations, the greatest value comes from combining electronic information with direct observation rather than relying exclusively on either source.

Collision Avoidance for Sailing Vessels - Early Decisions Usually Provide More Options

Many collision situations become difficult because decisions are delayed unnecessarily. A skipper may continue observing a developing situation while waiting for confirmation that action is required. In the meantime, available options gradually reduce and any eventual manoeuvre becomes more obvious and more abrupt.

One theme that runs through every aspect of sailing situational awareness is that early recognition preserves options. Wind shifts, sea-state changes, weather developments and depth concerns all reward early action. Collision avoidance is no different. A small and obvious alteration of course made early is often preferable to a significant manoeuvre made later.

Collision Avoidance for Sailing Vessels - Practical Example

Several times aboard La Jonquille, I have altered course earlier than strictly necessary simply because the developing situation was becoming increasingly obvious. The manoeuvre was usually small and had little impact on the passage plan, yet it removed uncertainty entirely. In hindsight, those decisions nearly always proved easier than waiting for the situation to become more constrained.

Collision Avoidance for Sailing Vessels - My Meerkat Mentality

One habit I have developed aboard La Jonquille and all my previous boats is what I call the meerkat mentality. Every ten or fifteen minutes I stand up and have a proper look around, regardless of what AIS, radar or the chartplotter might be showing. I scan the entire horizon, look astern, check ahead of the mast and deliberately look into any area hidden by sails or rigging. If I need to move around the cockpit to clear a blind spot, I do.

The purpose is simple. I want to know what has changed since the last scan. Has a vessel appeared where there wasn't one before? Has that ship altered course? Is there a fishing boat hidden under the genoa? Has the weather changed? I am not just looking for traffic, I am rebuilding my mental picture of everything happening around the boat.

Over the years, that simple habit has probably identified more potential issues than any electronic aid aboard my boat. Small fishing boats, poorly lit vessels, crab and lobster trap floats, floating debris and developing weather are often spotted by looking outside long before they become obvious on a screen. Electronics are excellent tools and I use them constantly, but they support situational awareness, they do not create it. For me, collision avoidance still starts with the meerkat mentality, stand up, look around and keep asking myself what has changed since the last time I looked.

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Collision Avoidance Is Ultimately a Situational Awareness Skill

After years of sailing both racing dinghies and cruising yachts, I have come to view collision avoidance primarily as a situational-awareness skill. The collision regulations provide the framework, but awareness provides the time needed to use that framework effectively.

Good skippers rarely appear surprised by vessel traffic because they have been evaluating developing situations for a considerable period beforehand. They understand what is happening around them, what is likely to happen next and which options remain available. That awareness reduces workload, improves decision-making and generally prevents situations from becoming urgent.

Collision Avoidance for Sailing Vessels - Practical Example

Many of the best collision-avoidance decisions I have made aboard La Jonquille were almost invisible. No dramatic manoeuvre was required and no close-quarters situation developed. The reason was simple. The risk had been recognised early and dealt with while options remained plentiful. In many respects, that is exactly what effective collision avoidance should look like.

Collision Avoidance for Sailing Vessels - Frequently Asked Questions

• What is the most reliable sign of collision risk? A vessel maintaining a constant bearing while the range continues decreasing is one of the strongest indicators that further assessment is required.
• What does constant bearing mean? It means another vessel appears to remain in the same relative direction from your boat while the distance between the two vessels decreases.
• Should sailors rely entirely on AIS? No. AIS is an excellent tool, but it complements rather than replaces a proper lookout and visual observation.
• Does fatigue increase collision risk? Yes. Fatigue can reduce situational awareness and make it harder to identify developing traffic situations early.
• How far away should collision avoidance begin? In my experience, as early as practical. Early recognition generally provides more options and requires smaller course alterations.
• Is collision avoidance mainly about knowing the rules? The regulations are important, but effective collision avoidance depends heavily on maintaining awareness and recognising risk before close-quarters situations develop.

Collision Avoidance for Sailing Vessels - Summary

Over years of racing dinghies and cruising aboard La Jonquille, I have learned that collision avoidance is primarily an observation and anticipation skill. Most risks develop slowly and provide plenty of warning for skippers who maintain an effective lookout and assess relative movement. The key is recognising developing situations early. A vessel observed and understood miles away is far less likely to become a problem than one noticed only when action is unavoidable. Collision Avoidance for Sailing Vessels for all you need to know.