Question 1

You are on course 090° at 14 knots. There is a vessel 2nm ahead on course 085° at 9 knots. Her bearing is 082° from you. You are closing. Does Rule 13 (Overtaking) apply, or Rule 15 (Crossing)?

Accepted Answer

Rule 13 — Overtaking — applies when a vessel is coming up on another from a direction more than 22.5° abaft the beam of the vessel being overtaken. Rule 13(b): a vessel shall be deemed to be overtaking when she can see ONLY the sternlight of another vessel (i.e., she is within the 135° sternlight arc — more than 22.5° abaft the beam on either side). In this scenario: the vessel ahead is bearing 082° — your own course is 090°, so the other vessel is 8° to the LEFT of dead ahead — she is well forward of your beam, not abaft it. This is NOT an overtaking situation. The two vessels are on approximately parallel courses with yours slightly more to the right — this is likely a crossing situation (Rule 15) or potentially a head-on situation (Rule 14) requiring analysis of the other vessel's heading relative to yours. Determine the other vessel's aspect by observing which sidelight is visible. Rule 13 is specifically tested to identify whether candidates confuse "faster than the vessel ahead" with the precise legal definition of overtaking. Rule 13(b) defines overtaking geometrically, not by speed: a vessel is overtaking if it approaches from more than 22.5° abaft the BEAM of the other vessel — i.e., it can see only the other vessel's sternlight (the 135° arc centred on the stern). In the scenario: the other vessel is bearing 082° from the overtaking vessel at 090° own course — this puts the other vessel nearly dead ahead, well within the forward hemisphere. You cannot be overtaking a vessel that is approximately ahead of you. The correct analysis: observe the other vessel's sidelights — if green (starboard) is visible, she is crossing from right to left (or heading away slightly to your right); apply Rule 15 if both are underway and crossing. Rule 13(d): "if in any doubt whether she is overtaking another, she shall assume that this is the case and act accordingly." However, this applies when the geometry is genuinely ambiguous (vessel just abaft the beam in borderline cases), not when the geometry clearly indicates a different rule applies.

Question 2

You are OOW on a power-driven vessel underway. You have five vessels near you: a sailing vessel, an NUC vessel, a vessel engaged in fishing, a RAM vessel, and a CBD vessel. Your examiner asks you to rank your responsibilities to each in order.

Accepted Answer

Rule 18 establishes the hierarchy for power-driven vessels underway. In order of priority (highest first — you must give way to all of these in this order): 1st — NUC (not under command): cannot manoeuvre, ultimate priority — Rule 18(a)(i); 2nd — RAM (restricted in ability to manoeuvre): limited manoeuvring ability — Rule 18(a)(ii); 3rd — CBD (constrained by draught): cannot deviate from channel — Rule 18(a)(iii) [note: CBD is optional display — not all CBD vessels show the signal]; 4th — FISHING (engaged in fishing with gear): Rule 18(a)(iv) — note this means fishing with nets/lines, NOT a vessel that has fishing equipment on board but is not actually fishing; 5th — SAILING VESSEL: Rule 18(a)(v) — power gives way to sail (with exceptions in Rule 18(b) where a sailing vessel overtaking a power-driven vessel must keep clear). You must keep out of the way of all five in this order. Rule 18 — Responsibilities Between Vessels — is one of the most fundamental OOW exam topics. The hierarchy from Rule 18(a): (i) NUC; (ii) RAM; (iii) CBD; (iv) fishing; (v) sailing; all are given way over by power-driven vessels. The rules are additive — if you must give way to a CBD vessel, you also must give way to all ranks above it. Key nuances tested at OOW level: (1) CBD is only recognised as a privileged vessel if it displays the signal — a vessel that is constrained by draught but shows nothing is treated as a power-driven vessel; (2) A vessel fishing = one that has gear restricting its ability to manoeuvre; a vessel with rods trolling or no gear deployed = treated as a power-driven vessel; (3) Sailing vessel with engine running (motorsailing) = treated as a power-driven vessel (shows day shape — cone point down); (4) Rule 18(b): nothing in Rule 18 exempts a sailing vessel from keeping clear when overtaking another vessel. The exam will present scenarios where the candidate must apply the correct rule from this hierarchy.

Question 3

You are the stand-on vessel in a crossing situation. The give-way vessel is not taking action. At what point and how do you act under COLREGs Rules 16 and 17?

Accepted Answer

Rule 17 stand-on obligations: (a)(i) — maintain course and speed initially; (a)(ii) — when it becomes apparent the give-way vessel is NOT taking appropriate action, the stand-on vessel MAY take action to avoid collision by her manoeuvre alone; (b) — when a collision cannot be avoided by the give-way vessel alone, the stand-on vessel SHALL take action. The timing sequence: (1) Initially: maintain course and speed — Rule 17(a)(i); (2) Give-way not acting, situation developing: you MAY act to help (Rule 17(a)(ii)) — but only by altering to starboard (not to port for a vessel on your port side, as this creates confusion); (3) Imminent collision, no action possible by give-way alone: you MUST act — Rule 17(b). Sound signal Rule 34(d): if in doubt about another vessel's intentions, give at least 5 short blasts on the whistle immediately. Rule 17 is nuanced and consistently examined. The three stages: mandatory hold (17(a)(i)), permissive action (17(a)(ii)), mandatory action (17(b)). The timing of transition from stage 1 to 2 to 3 is a matter of seamanlike judgement — the examiner will probe this. Key point: Rule 17(c) — when the stand-on vessel takes action under Rule 17(a)(ii) to avoid collision, she shall, if the circumstances of the case admit, NOT alter course to PORT for a vessel on her own PORT side. The reason: if both vessels try to pass to starboard of each other (own vessel altering starboard, give-way vessel finally altering starboard) they could collide — the COLREGs design assumes the stand-on vessel will also go starboard if it must act. Altering to port by the stand-on vessel for a vessel crossing from port risks a collision if both alter in the same direction. Rule 34(d) five short blasts: this is the signal for doubt about the other vessel's intentions or actions to avoid collision — it is NOT the action itself; it alerts the other vessel that action may be necessary.