Give-way, Stand-on and Responsibilities between Vessels

Give-way and stand-on: who does what

In short: Read Risk of Collision and Action to Avoid Collision and Overtaking, Head-on and Crossing Situations first. When two vessels in sight of each other meet with risk of collision, the rules usually make one the give-way vessel (keeps out of the way) and the other the stand-on vessel (keeps her course and speed). Rule 18 decides who is who when the two vessels are of different kinds.

• COLREG Rule 16 — the give-way vessel takes early and substantial action to keep well clear, so far as possible.
• COLREG Rule 17 — the other vessel is the stand-on vessel: she keeps her course and speed, with the SHALL–MAY–SHALL steps below.
• Who gives way comes from: Rule 13 (the overtaking vessel), Rule 15 (two power-driven vessels crossing: the one with the other on her own starboard side), Rule 12 (two sailing vessels) and Rule 18 (vessels of different kinds).
• No stand-on vessel in two cases: head-on (Rule 14 — both alter to starboard) and restricted visibility with vessels not in sight (Rule 19 — every vessel acts).
• Rules 11–18 (Part B, Section II) apply only to vessels in sight of one another (COLREG Rule 11).
• COLREG Rule 2 sits above all of this. 2(a): nothing excuses neglect of the rules or of the ordinary practice of seamen. 2(b): you may depart from the rules when needed to avoid immediate danger, with due regard to all dangers and special circumstances. Examiners do ask “Rule 2” on its own.

Rule 17 — SHALL, MAY, SHALL

In short: The stand-on vessel goes through three stages: she shall keep course and speed, she may act alone once the give-way vessel is clearly not doing enough, and she shall act when collision can no longer be avoided by the give-way vessel alone.

• Holding course and speed matters: the give-way vessel builds her plan on you not changing. An unexpected change can cancel her action.
• Before stage 2, if you doubt the other vessel’s intentions, sound at least five short and rapid blasts (COLREG Rule 34(d)). Call the Master.
• Rule 17(c) — a power-driven vessel acting under 17(a)(ii) in a crossing with another power-driven vessel shall, if the circumstances admit, not alter to port for a vessel on her own port side. Reason: the give-way vessel will most likely turn to starboard, late — a turn to port meets her turn.
• Rule 17(d) — nothing in Rule 17 releases the give-way vessel from her duty to keep out of the way.

The vessel being overtaken

• Favourite oral question: “Rule 13 — must the vessel being overtaken keep her course and speed?”
• Rule 13 says nothing about her: it puts the whole duty on the overtaking vessel.
• Her duty comes from Rule 17(a)(i): where one of two vessels must keep out of the way, the other keeps her course and speed. So yes — she is the stand-on vessel, and SHALL–MAY–SHALL applies to her too.

On the bridge: the give-way ship does nothing

• Crossing situation, a power-driven ship on your port bow, bearing steady, CPA close to zero. She is the give-way vessel. You stand on and keep plotting.
• Range closing, still no action → sound five short blasts, call the Master. Once it is apparent she is not acting, you may act alone: a bold turn to starboard (often a full round turn) or reduce speed / stop. Not to port (17(c)).
• If she is now so close that her own action cannot avoid collision, you must act (17(b)) — whatever best avoids or reduces the collision, e.g. hard over and engines full astern.

Rule 18 — the pecking order

In short: Except where Rules 9, 10 and 13 say otherwise, the more manoeuvrable vessel keeps out of the way of the less manoeuvrable one. NUC and RAM sit at the top, the power-driven vessel at the bottom.

• Memory aid, top to bottom: “Never Run Close — Fishermen Sail Past” = NUC, RAM, CBD, Fishing, Sailing, Power.
• The three exceptions: Rule 13 (an overtaking sailing or fishing vessel still keeps clear), Rule 9 (narrow channels) and Rule 10 (TSS), where sailing vessels, vessels under 20 m and fishing vessels must not impede — see Rule 8(f) below.
• Two sailing vessels: Rule 12, not Rule 18. Two power-driven vessels: Rules 13–15.
• “Avoid impeding” a CBD is not the same as “keep out of the way”: you act early so that she never has to manoeuvre.

Who counts as what (COLREG Rule 3)

• Power-driven vessel: any vessel propelled by machinery.
• Sailing vessel: any vessel under sail, provided her propelling machinery, if fitted, is not being used. Motor-sailing = power-driven.
• Vessel engaged in fishing: fishing with nets, lines, trawls or other gear that restricts her manoeuvrability. Not trolling lines or other gear that does not restrict her. The rules speak of a vessel “engaged in fishing”, never of a “fishing vessel”: a trawler on passage with her gear stowed is just a power-driven vessel.
• Trawling ≠ trolling: a trawler towing a trawl is engaged in fishing; a boat trolling lines is not.
• Seaplane: any aircraft designed to manoeuvre on the water.
• NUC: a vessel that, through some exceptional circumstance, cannot manoeuvre as the rules require. A planned engine shutdown is not NUC.
• RAM: a vessel restricted in her ability to manoeuvre by the nature of her work (e.g. dredging, surveying, cable laying, replenishment at sea, a tow that severely restricts her ability to deviate from her course).
• CBD: a power-driven vessel that, because of her draught in relation to the available depth (and width) of navigable water, is severely restricted in her ability to deviate from her course. By definition she stays a power-driven vessel; for lights and shapes she adds her own signals (Rule 28: three all-round red lights or a cylinder).
• Towing or pushing: a power-driven vessel engaged in towing or pushing. Towing alone gives no rank in Rule 18.

Ranks can change

• The other ship can lose steering or power, or have a fire: she becomes NUC and moves to the top of Rule 18. Keep monitoring her lights, shapes and behaviour all the way.
• A vessel that runs aground switches to aground lights and shapes.
• A trawler that hauls her gear and heads home drops from “engaged in fishing” to plain power-driven vessel.

Rule 18 meets Rule 15 — turning to port, tugs and tows

In short: Rule 15 is only for two power-driven vessels. If the crossing vessel is NUC, RAM, engaged in fishing or sailing, Rule 18 makes you give way even when she is on your port side — and a turn to port to pass astern of her can be the right action.

• You are the give-way vessel here, so Rule 17(c) (no turn to port) does not apply to you: it binds a stand-on vessel.
• Rule 13 still beats Rule 18: a fishing or sailing vessel that is overtaking you keeps clear of you.
• Tug with a tow — check her signals first:
  • Showing RAM (ball–diamond–ball by day; red–white–red all-round lights at night): her tow severely restricts her ability to deviate from course. She ranks at the top: you keep clear, wherever she is.
  • Only towing lights and shapes (no RAM signals): she is a plain power-driven vessel towing. Rule 15 applies as normal: on your port side, she gives way to you.
• Never pass between a tug and her tow. The tow wire can be very long (around 800 m for a jack-up rig towed by a 120 m anchor-handling tug), and some tows (e.g. fish-farm cages) sit low and are hard to see.

On the bridge: a trawler crossing

• At night you see green over white all-round lights and her green sidelight: she is crossing, she has you on her starboard side, so she is on your port side. She is shooting her nets astern.
• Under Rule 15 alone she would give way. But green over white = trawling = engaged in fishing (Rule 3(d)), so Rule 18(a) applies: you keep out of the way.
• Your options:
  • take a series of compass bearings to confirm the risk;
  • nets astern of unknown extent → do not cross close astern of her;
  • a round turn;
  • alter to starboard, run parallel, then pass astern at a good distance (or ahead, only if you are much faster and clearly clear);
  • take all way off and let her pass.

Rule 8(f) — “not to impede”

In short: Some vessels must not impede others. That means acting early so that a risk of collision never develops. It is not the same as “keep out of the way”, it does not end when risk of collision appears, and the vessel you protect is not released from the rules.

• Where the duty appears:
  • Rule 9(b) — a vessel under 20 m or a sailing vessel must not impede a vessel that can navigate safely only inside a narrow channel.
  • Rule 9(c) — a vessel engaged in fishing must not impede any other vessel navigating inside a narrow channel.
  • Rule 9(d) — do not cross a narrow channel if that impedes a vessel that can navigate only inside it.
  • Rule 10(i) — a vessel engaged in fishing must not impede a vessel following a traffic lane.
  • Rule 10(j) — a vessel under 20 m or a sailing vessel must not impede a power-driven vessel following a traffic lane.
  • Rule 18(d) — avoid impeding a CBD.
• Rule 8(f)(i) — the vessel that must not impede takes early action to leave enough sea room for the other’s safe passage.
• Rule 8(f)(ii) — she is not released from this duty if the two vessels close to a risk of collision, even if the steering rules would make her stand-on. When she acts, she must still respect the Part B steering rules.
• Rule 8(f)(iii) — the vessel whose passage must not be impeded stays fully bound by Part B when risk of collision develops. She does not become “privileged”.
• Rule of thumb from tanker practice (not a COLREG figure): if you are within about 3 NM of a large ship and forward of her beam, you are probably impeding her.
• On the bridge: a 15 m sailing yacht crosses a TSS lane with a laden tanker approaching from the yacht’s port side. Rule 18 alone would make the tanker give way. But Rule 10(j) and 8(f)(i) make the yacht act early so the tanker never has to manoeuvre. If they still close to risk of collision, the yacht keeps acting (8(f)(ii)) and the tanker must apply the steering rules too (8(f)(iii)).

Give-way action: check it, then resume

In short: Your action must follow Rules 11–19, be obvious to the other ship and give a safe passing distance. Then check it until finally past and clear, and only resume course and speed when the CPA stays safe.

• Actions must comply with COLREG Rules 11–19 (Part B). Real life is rarely one-to-one: crossing, overtaking and head-on at once, usually at night or in restricted visibility. Then you need a series of actions, prioritised by each target’s CPA/TCPA.
• Coordinated action: if both ships manoeuvre, their changes should move the relative motion line the same way, so the CPA increases. Check with a trial manoeuvre (plus a manual plot) before you commit.
• Your CPA limit is the guide: if you want 1 NM, act on anything under 1 NM. Also set a minimum BCR (bow crossing range). Increase both for large ships, tows and at close range.
• COLREG Rule 8(d) — check the effectiveness of your action until the other vessel is finally past and clear. Three criteria:
  1. the action follows the COLREG;
  2. it is visible to the other ship, by eye or on radar (large, not a series of small changes);
  3. the ships pass at a safe distance.
• Resuming course and speed (Rule 8): your return must not create another close-quarters situation. “Past and clear” = a safe CPA even after you restore course and speed — the trial manoeuvre shows when.
• A safe distance allows for interaction, yaw, a sudden sheer, and an engine or rudder failure on either ship.

Fog: nobody stands on

• In restricted visibility, with vessels not in sight, Rule 19 applies: no give-way and no stand-on vessel — every vessel takes avoiding action.
• First steps: reduce speed, inform the Master, post an extra look-out (AB or deckhand).
• Example: container ships making 22 kn slow to 6–7 kn in North European fog banks. Better to arrive late than not to arrive: stand your ground with owners and charterers.