What is the rule 18 for ships
So Rule 18 of the COLREGs? It's basically the big boss of who yields to who at sea. It sets up this clear chain of command between different types of vessels when they can actually see each other and might collide. The whole point is to stop confusion and make sure everyone knows what to do based on how maneuverable a ship is and what it's doing right now. Without it, things would get real messy real fast.
How Does Rule 18 Establish Vessel Priority?
Think of it like a strict pecking order based on how badly a ship can steer out of trouble. The less maneuverable you are, the more everyone else has to get out of your way. Here's how it stacks up, from top dog to bottom:
- Vessel not under command (NUC): Something's gone wrong—maybe engine failure or steering's busted—and she just can't maneuver like the rules expect.
- Vessel restricted in her ability to maneuver (RAM): Her work itself limits her, like laying cables, dredging, or doing survey stuff. She's stuck doing her job.
- Vessel engaged in fishing: If she's using nets, lines, trawls, anything that cramps her style, she's in this bracket. Not just any fishing boat—only those actually restricted by their gear.
- Sailing vessel: Under sail only, no engines running for propulsion. Wind-powered, basically.
- Power-driven vessel: Pretty much anything with a motor pushing it along.
So a power boat has to give way to a sailboat, which gives way to a fishing boat, and so on up the chain. But remember—this only matters if they can actually see each other. No fog, no radar-only situations here.
What Are the Specific Responsibilities Under Rule 18?
Rule 18 breaks down into a bunch of sub-rules that spell out exactly who does what. The meat of it is:
- Rule 18(a)(i): Power-driven vessel underway? She's gotta stay clear of any NUC vessel.
- Rule 18(a)(ii): Same power-driven vessel also has to avoid a RAM vessel.
- Rule 18(a)(iii): And yep, she's got to steer clear of fishing vessels too.
- Rule 18(a)(iv): Plus sailing vessels are on the list—power gives way again.
- Rule 18(b): Sailing vessel underway has to keep out of the way of NUC, RAM, and fishing boats. She's not at the top.
- Rule 18(c): Fishing vessel underway? She should, as much as possible, stay out of the way of NUC and RAM vessels. Not a hard rule, but best practice.
- Rule 18(d): Any vessel that's not NUC or RAM should, if they can, avoid messing up the safe passage of a vessel constrained by her draft—the ones showing the special signals from Rule 28.
Rule 18 and Vessel Constrained by Her Draft
Rule 18(d) is where it gets a bit fuzzy. A "vessel constrained by her draft" means a power-driven ship that, because of how deep she sits in the water versus the depth available, can't really change course much. She's not given the same "right of way" as an NUC or RAM vessel—instead, others just need to "avoid impeding her safe passage." That's weaker language than "keep out of the way," but still means you gotta act early to not create a dangerous situation.
Here's the thing though—just because she's constrained doesn't make her the stand-on vessel automatically. She still has to follow other steering rules (like Rules 12-17) when there's a risk of collision with a ship that isn't required to avoid impeding her. It's complicated, yeah.
What is the Difference Between "Keep Out of the Way" and "Avoid Impeding"?
Getting these two phrases right is key to using Rule 18 properly. They're not the same thing at all.
| Action | Meaning | When Used |
|---|---|---|
| Keep out of the way | The give-way vessel must take early, big action to stay well clear. The stand-on vessel holds her course and speed. | Between vessels of different priority (like power vs. sail). |
| Avoid impeding | Don't make the other ship alter course or speed to avoid a close call. Less strict than "keep out of the way" and doesn't give automatic right of way. | Specifically for vessels constrained by draft under Rule 18(d). |
Frequently Asked Questions
Does Rule 18 apply in all visibility conditions?
Nope. Only when vessels can actually see each other. In restricted visibility, you're looking at Section II rules (4-10), which focus on safe speed and actions based on radar or other sensors. Different ball game entirely.
What happens if two vessels have the same priority under Rule 18?
If they're in the same category—two power-driven ships, for example—Rule 18 steps aside. Then other rules kick in: Rule 14 for head-on situations, Rule 15 for crossing, or Rule 16 for give-way vessel actions. Standard stuff.
Is a vessel engaged in fishing always the stand-on vessel?
Not always. She still has to give way to NUC and RAM vessels under Rule 18(c). It's about protecting the most vulnerable, not giving fishing boats a free pass.
How does Rule 18 interact with traffic separation schemes (TSS)?
Rule 18 doesn't override TSS rules (Rule 10). Even in a TSS, a vessel might have to give way to someone crossing the scheme. But NUC and RAM vessels should be avoided by everyone, TSS or not. Common sense, really.
Resumen breve
- Jerarquía de prioridad: Rule 18 establece un orden claro: buque sin gobierno (NUC) > buque con capacidad de maniobra restringida (RAM) > buque pescando > buque de vela > buque de propulsión mecánica.
- Obligación de apartarse: Un buque de propulsión mecánica debe apartarse de la derrota de todos los buques con mayor prioridad. Un buque de vela debe apartarse de NUC, RAM y buques pescando.
- Buque de calado limitado: Otros buques deben evitar impedir el paso seguro de un buque de calado limitado, aunque esto no le otorga derecho de paso absoluto.
- Aplicación limitada: La regla solo se aplica cuando los buques están a la vista. No anula las reglas de visibilidad reducida ni las de los dispositivos de separación de tráfico.
