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16

Action by Give-way Vessel

After an illustrative avoiding manoeuvre, give-way vessel A passes astern of B. Early and substantial action helps keep well clear. This unscaled scene prescribes no universal turn angle and does not prove a numerical passing distance.

1The rule in plain words

In one sentence…

If you are directed to keep out of the way, take early, substantial action to keep well clear.

When do you act?

If you are directed to keep out of the way, do not wait: act as early as possible.

How substantial must it be?

A token alteration is not enough: take substantial action, not a hesitant gesture.

What is the aim?

Your action must leave the other vessel clearly separated: keep well clear of her.

2Key points

  1. 1.

    Give-way duty → act.

  2. 2.

    Early · substantial · well clear.

  3. 3.

    Early means before the situation tightens.

  4. 4.

    Action must achieve clear separation from the other vessel.

3Frequent mistakes

  • Wrong: "A tiny late alteration is enough."

    Right: COLREG requires early and substantial action, not a token last-minute move.

  • Wrong: "I can cross ahead if I eventually clear the other vessel."

    Right: Your action must keep you well clear; merely getting past is not the test.

  • Wrong: "I can wait until the other vessel reacts."

    Right: The vessel directed to keep out of the way must take the action.

4Exam keys & interpretation

Exam keys

  • Spot both qualifiers: "early" and "substantial"; missing either changes the answer.

  • "Keep well clear" is the result being tested, not merely making an alteration.

  • "So far as possible" qualifies the action; it does not erase the give-way duty.

How to read it

  • Read Rule 16 as a three-part test: early action, substantial action, and a result that keeps you well clear.

  • "So far as possible" asks for the strongest practicable action; it is not permission to delay.

5Official text

IMO COLREG 1972U.S. Coast Guard — International Navigation Rules (2024)

Full wording of the rule, reproduced from the official source below.

Every vessel which is directed to keep out of the way of another vessel shall, so far as possible, take early and substantial action to keep well clear.
Source:

6Test your knowledge

Question 1/4

When must the give-way vessel act?

More questions on this rule →

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Frequently asked questions about COLREG Rule 16

What must the give-way vessel do under COLREG Rule 16?

Every vessel which is directed to keep out of the way of another vessel shall, so far as possible, take early and substantial action to keep well clear.

How early must the give-way vessel act?

Early — not at the last moment. The action must be early, substantial and effective: clearly visible to the other vessel and resulting in a safe passing distance, so that the goal is to keep well clear rather than to barely avoid collision.

Why are small course changes a problem for the give-way vessel?

Because the action has to be substantial and readily apparent to the other vessel. Making small course changes the other vessel cannot notice, and acting only once the vessels are already close, are the usual Rule 16 failures.