Is rule 13 applicable in restricted visibility

So, Rule 13 of the COLREGs—that's the bit about overtaking. People get confused about whether it even matters when you can't see a damn thing. Short answer? Yeah, it absolutely does. But it gets tangled up with Rule 19, which is all about how you handle yourself in restricted visibility. It's not either/or, it's both.

Understanding Rule 13: The Overtaking Rule

Rule 13 says you're overtaking if you're coming up on another vessel from more than 22.5 degrees behind their beam. Simple enough. The overtaking boat—doesn't matter if it's sail or power—has to stay the hell out of the way. That's it. Early action, substantial action. Don't be that guy who waits until the last second.

Does Rule 13 Apply in Restricted Visibility?

Yes. No ifs, ands, or buts. The rules don't give you a pass just because it's foggy. But here's the thing—when you can't see, you're relying on radar, AIS, and sound signals instead of your eyeballs. The overtaking vessel still has to keep clear, but you're figuring out the situation through electronics now. It changes how you do it, not whether you do it.

Interaction Between Rule 13 and Rule 19

Rule 19 is your bible in restricted visibility. Safe speed, engines ready, avoiding action based on radar. When you detect an overtaking situation on radar, Rule 13 tells you who gives way, and Rule 19 tells you how to do it safely. The overtaking vessel can't cross ahead. Period. You take action early, not when it's too late.

Practical Considerations for Mariners

In fog, you're using radar to check relative bearing and closing speed. Target abaft the beam and getting closer? That's overtaking. You should alter course to starboard—or port if it makes sense and is safe—to give plenty of room. Sound signals under Rule 34 can help, but they're not mandatory. The overtaken vessel just holds course and speed unless things get dicey.

Common Misconceptions and Clarifications

I've heard people say that in restricted visibility, every vessel becomes a "power-driven vessel" for the rules. That's just wrong. Rule 13 still cares about whether you're sail or power. But honestly? In thick fog, you probably can't tell what type of vessel you're dealing with. So assume the worst and act accordingly. The overtaking vessel always gives way, no matter what the visibility is like.

Data Table: Rule 13 vs. Rule 19 in Restricted Visibility

Checklist for Overtaking in Restricted Visibility

• Check that target is more than 22.5 degrees behind your beam—use radar or AIS.
• Make sure you're the faster one closing in.
• Plot that risk of collision with radar or ARPA.
• Act early and decisively—alter course to starboard if you can.
• Sound one short blast if you're changing course to starboard (Rule 34).
• Keep your speed safe under Rule 19.
• Watch the other vessel—be ready to do more if needed.
• Radar on, lookout sharp, all means available.

People Also Ask: Expert Answers

What is the difference between overtaking and crossing in restricted visibility?

Overtaking is when you come from more than 22.5 degrees behind the beam. Crossing is... well, anything else that's not head-on. In restricted visibility, Rule 19 kind of overrides the crossing rule—both vessels have to take action. But for overtaking, Rule 13 still holds. The overtaking boat gives way.

Can a vessel being overtaken change course in restricted visibility?

The stand-on vessel under Rule 13 should hold course and speed. But Rule 19 says both vessels must act if there's risk of collision. If the overtaking vessel isn't doing its job, the overtaken boat might have to maneuver. Just don't turn to port across the overtaking vessel's bow. That's asking for trouble.

How does radar help in applying Rule 13 in fog?

Radar is your best friend here. You can see if a target is abaft the beam and closing. Range rate tells you if you're overtaking. Plotting or ARPA gives you CPA and TCPA. All that helps you take early action—like altering course to increase passing distance.

What sound signals should be used when overtaking in restricted visibility?

Fog signals under Rule 35 are mandatory. For overtaking, you might also use Rule 34 signals to show intent—like one short blast for a starboard turn. The other vessel can echo it if they agree. But these signals are optional in restricted visibility. Focus on safe maneuvering first.

Expert Insights on Rule 13 in Restricted Visibility

Experts will tell you Rule 13 isn't suspended just because you can't see. The overtaking vessel is always the give-way vessel. But you've got to be more vigilant. Use radar, AIS, sound signals—everything. Take positive action early. In dense fog, maybe slow down or even stop if you're not sure. Don't assume anything. Safety comes first, always.

FAQ: Rule 13 in Restricted Visibility