Rule 19 in restricted visibility: proceed at a safe speed and maintain a proper look-out.

Outline

• Hook: In restricted visibility, two simple duties do the heavy lifting: slow down when you should, and keep eyes and ears on the job.

• Section 1: What Rule 19 really requires

• Safe speed

• Proper look-out

• What not to do (briefly debunking other options)

• Section 2: Why safe speed is a lifesaver in fog, rain, or twilight

• Examples of hazards that aren’t obvious

• Section 3: How to maintain a proper look-out, even when the radar hums softly

• Roles on deck, listening, and using gear without overreliance

• Section 4: Practical tips you can actually apply

• Quick, everyday steps for restricted visibility

• Section 5: Common myths and quick clarifications

• Section 6: A few real-world analogies to keep it human

• Conclusion: Readiness beats bravado on the water

• Call to action: Stay curious about the rules that keep sailors safe

In restricted visibility, two simple duties do the heavy lifting

Let me set the scene. Imagine the sea is playing hide-and-seek with you—fog hugs the bow, rain pelts the deck, and twilight blurs the horizon. In moments like these, Rule 19 of the COLREGs isn’t just a line on a paper map; it’s a lifeline. The rule says vessels must proceed at a safe speed and maintain a proper look-out. That’s the script, but there’s real craft in how you live it on board.

What Rule 19 actually requires: two straightforward duties, two quiet shifts in your thinking

• Proceed at a safe speed

Think of speed as a measured response, not a guess. When visibility is restricted, you need to be able to stop or maneuver in time to avoid a collision. Safe speed isn’t about crawling along or hitting the brakes at the last second; it’s about choosing a pace that matches conditions, traffic, weather, and maneuverability of your vessel. If you can’t respond promptly to a sudden obstacle or an unseen vessel, your speed isn’t safe. It’s as simple—and as essential—as that.

• Maintain a proper look-out

A proper look-out isn’t just someone peering over the rail like a lighthouse keeper. It’s a full-sensory, collaborative effort: eyes scanning, ears listening for engines, horns, or splash, and hands ready to interpret radar echoes, AIS targets, or radar plot changes. In restricted visibility, the crew stays alert, communicates clearly, and continually updates what they’re seeing or predicting. It’s a teamwork routine: someone watches, someone listens, someone confirms. The look-out keeps the ship informed about what’s around, even when the water seems empty.

What Rule 19 isn’t asking for (the common misfires)

• No need for continuous alarms

While sound signals can be part of a broader safety plan, Rule 19 isn’t about sounding alarms endlessly. Alarms might be appropriate in certain situations, but the core duty in restricted visibility is to move safely and keep a vigilant lookout, not to flood the air with noise.

• Not “use only radar” for navigation

Radar is a powerful tool, yes, but Rule 19 doesn’t demand exclusive reliance on it. A proper look-out uses all available information—visual observation, radar, AIS, sound signals, and communications with other vessels. It’s a multi-tool approach, not a single instrument fix.

• Not “do not change course”

In restricted visibility, you might still need to adjust course as traffic and hazards reveal themselves. Rule 19 emphasizes safe speed and a proper look-out, not a rigid, unchanging path. Flexibility, guided by good information, is often the safer play.

Why safe speed matters: fog, rain, twilight—reality doesn’t wait

If you’ve ever driven a car with limited visibility, you know speed changes everything. The same logic applies at sea, but with bigger consequences and different constraints.

• Hidden hazards can pop up suddenly

A sailboat lurking in the mist, a fishing vessel weaving through a channel, or a buoy you don’t clearly see until it’s almost at the bow—these aren’t character flaws in your vessel. They’re realities of low visibility. If you’re moving at a cautious speed, you preserve the time and space needed to identify and respond to such hazards.

• Stopping distance scales with weather and load

A fully laden ship or a high-wrecker tug needs more stopping distance than a light craft. Rain and swell can reduce maneuverability; fog can compress your perception of distance. Safe speed has to adapt to those factors, not pretend they don’t exist.

• It gives you patience—without losing momentum

Slowing down isn’t about fear; it’s about smart, deliberate preparation. You still navigate, you still communicate, you still keep a watch. You just do it with more room to react.

Keeping the look-out: a practical, human approach

A proper look-out is about presence of mind as much as presence on the bridge. Here’s how it tends to work in the real world:

• Teamwork on watch

One person scanning the horizon while another monitors radar and AIS is a solid baseline. If you’re the observer, you shout up any distant lights, unusual wakes, or changes in bearing. If you’re the radar watcher, you’re ready to cross-check with visuals and question any ambiguous marks on the screen.

• Listen as part of the sight

Sound carries differently in rain and fog. Listen for engines behind the fog, for the distinct hum of a vessel’s propeller, or the telltale echo of a fog signal. Sometimes sound reveals more than sight.

• Use gear as a guide, not a crutch

AIS and radar are valuable, but they don’t replace human judgment. An AIS target may appear as a friendly green icon, but you still verify by sight and by speed and bearing changes. Don’t treat technology as your sole navigator.

• Clear, concise communications

Short, direct messages with other vessels about headings, speeds, and intentions help prevent misreads. The point is to maintain a shared mental map of the traffic picture, especially when visibility is playing tricks on you.

Practical tips you can apply right now

• Slow down early, not late

As soon as you’re entering reduced visibility, consider trimming speed before you feel the pressure to react later. It’s easier to stop or turn when you have time.

• Establish a rigid look-out routine

Assign roles, rotate responsibilities, and keep the watch steady. A predictable routine reduces the chance of missing a hazard.

• Rely on more than one sense

Look, listen, and cross-check data. If you’re unsure about what you’re seeing on radar, slow down and verify with your eyes or with another instrument before acting.

• Use signals to share intent

If you’re approaching another vessel or a channel marker, use appropriate signals or radio communication to clarify your path and expectations. Clarity beats confusion in fog.

• Keep lights and markings visible

Proper navigation lights and day shapes aren’t just for show. They help other vessels understand your status and motion, especially when visibility is poor. Use them as part of your overall collision avoidance strategy.

Common myths—quick clarifications

• Myth: You should always keep the same course in restricted visibility.

Reality: You should adjust your course as needed to avoid collisions and to stay on a safe path. It’s smart navigation, not stubborn adherence.

• Myth: You can rely on radar alone.

Reality: Radar is a tool, not a guarantee. The look-out, the speed, and the human judgment behind the decisions matter just as much.

• Myth: The rule says you must proceed slowly at all times.

Reality: It’s about safe speed for the conditions, not simply crawling. You balance the need to move with the need to stay safe.

A few human-sized analogies to make it stick

• Think of driving through a heavy fog on a quiet road. You don’t speed up because you want to reach your destination faster; you slow down so you can react to a pedestrian stepping into the street or a curve you can’t quite see yet. The ocean operates on the same principle, just at a bigger scale.

• Picture a co-pilot at the helm. The co-pilot isn’t checking a box; they’re reading the weather, the traffic, and the boat’s performance, and they’re quietly coordinating with the captain to keep the ship steady. In restricted visibility, that teamwork becomes mission-critical.

Conclusion: readiness over bravado

Rule 19 isn’t designed to dazzle with drama. It’s written to keep people safe when the world shrinks to the sound of the engine and the beat of the radar. Procced at a safe speed and maintain a proper look-out—two simple phrases that pack a lot of practical wisdom. It’s not about fear; it’s about readiness, discipline, and trust in good seamanship.

If you’re curious about how these principles play out in real waterways, grab a moment to consider different weather scenarios and traffic patterns. Ask yourself how your crew would respond, what signals you’d rely on, and where you’d adjust speed or bearing to stay out of harm’s way. The more you visualize these situations, the more natural the rules feel when the fog rolls in.

In the end, safe speed and vigilant watchkeeping aren’t dry, abstract ideas. They’re the quiet backbone of every voyage, the margin between a smooth passage and a perilous misstep. Treat them with the respect they deserve, and you’ll navigate not just the weather, but the uncertainties that every sailor faces.