1.9 Give-Way & Stand-On Responsibilities (Rules 16-17)

The Two Roles

Most encounters between vessels resolve into a give-way vessel (the one required to keep out of the way) and a stand-on vessel (the one required to hold course and speed). Rules 16 and 17 define the duties of each role. They are short, precise, and among the most heavily tested rules on the OUPV exam because the stand-on vessel's obligations shift as a dangerous situation develops.

Rule 16 — Action by the Give-Way Vessel

"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."

Three loaded words:

• Early — act while the vessels are still well apart, giving the maneuver time to work and the other operator time to see it.
• Substantial — a bold, obvious change (this ties directly to Rule 8(b): large enough to be readily apparent; avoid a succession of small alterations).
• Well clear — the goal is not a near miss but a comfortable, safe passing distance.

As give-way vessel you own the outcome. Do not wait, do not nibble at the problem with tiny course changes, and do not assume the stand-on vessel will fix your geometry for you.

Rule 17 — Action by the Stand-On Vessel

Rule 17 is a staged rule: the stand-on vessel's obligations change in three steps as the situation deteriorates.

Stage 1 — Hold course and speed (17(a)(i))

"Where one of two vessels is to keep out of the way the other shall keep her course and speed."

The purpose is predictability. If the stand-on vessel starts maneuvering early, the give-way vessel cannot plan a safe pass, and the two may maneuver into each other. So the stand-on vessel's first duty is to be a steady, predictable reference: maintain course and speed.

Stage 2 — MAY take action (17(a)(ii))

"The [stand-on vessel] may however take action to avoid collision by her maneuver alone, as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action in compliance with these Rules."

When it becomes apparent that the give-way vessel is not acting (or not acting adequately), the stand-on vessel is permitted — not yet required — to maneuver on her own. This is the stand-on operator's early warning valve: you do not have to hold course blindly into a collision while the other vessel does nothing.

Stage 3 — MUST take action / in extremis (17(b))

"When, from any cause, the [stand-on vessel] finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision."

At the closest range, when the give-way vessel can no longer prevent the collision by itself, the stand-on vessel is required to act, taking whatever action will best aid to avoid collision. This is the in extremis stage, and it links back to Rule 2(b): the ordinary rules bend to the overriding duty to avoid immediate danger.

The port-turn restriction (17(c))

"A power-driven vessel which takes action in a crossing situation... to avoid collision with another power-driven vessel shall, if the circumstances of the case admit, not alter course to port for a vessel on her own port side."

Why? In a crossing situation the give-way vessel is normally the one on your starboard side, and she should be turning to starboard to pass astern of you. If you — the stand-on vessel — turned to port, you would turn into her intended path. So when the stand-on vessel acts under 17(a)(ii), she should not turn to port toward a vessel on her port side. (Note: in the true in-extremis stage under 17(b), the overriding duty is to do whatever best avoids collision, and the restriction gives way to necessity.)

Worked Example: When the Give-Way Vessel Does Nothing

You are the stand-on vessel in a crossing situation; a motor yacht is the give-way vessel approaching on your port side and should keep clear. Stage 1: you hold course and speed. As the range closes, the yacht shows no sign of slowing or turning — it becomes apparent it is not taking appropriate action. Stage 2: you are now permitted to maneuver on your own; because the yacht is on your port side, Rule 17(c) says do not turn to port toward it — a turn to starboard or a reduction in speed is appropriate. Stage 3: if it gets so close that the yacht alone can no longer avoid you, you must take whatever action best avoids collision — including, in true extremis, any maneuver at all, port turn included, because avoiding the collision now overrides the restriction.

Exam Framing

The exam probes the staging of Rule 17. Know that the stand-on vessel first holds course and speed; may act when the give-way vessel plainly is not acting; must act in extremis; and, in a crossing situation, should not alter course to port for a vessel on her own port side. Pair this with Rule 16's early and substantial action to keep well clear for the give-way side, and you have the complete give-way/stand-on picture the module is built around.