Question 1

You are OOW on a sailing vessel on port tack. You observe a sailing vessel on starboard tack 1nm to windward. What is the obligation and how do you act?

Accepted Answer

RULE 12 — SAILING VESSELS: RULE 12(a)(i): "When each has the wind on a different side, the vessel which has the wind on the port side shall keep out of the way of the other." PORT TACK VESSEL (wind from port, boom to starboard): this is the GIVE-WAY vessel when meeting a starboard-tack vessel. STARBOARD TACK VESSEL: this is the STAND-ON vessel. ASSESSMENT: your vessel (port tack) is the GIVE-WAY vessel. The starboard tack vessel to windward is the STAND-ON vessel. RULE 12(a)(ii): when both on the same tack — the vessel to windward is the give-way vessel. But in this scenario — different tacks, so 12(a)(i) applies. ADDITIONAL RULE 12(b): "If a vessel with the wind on the port side sees a vessel to windward and cannot determine with certainty whether the other vessel has the wind on the port or the starboard side, she shall keep out of the way of the other." This provision protects an uncertain port-tack vessel by requiring it to give way if it is unsure of the other vessel's tack. ACTION AS GIVE-WAY VESSEL: (1) Identify the STAND-ON vessel clearly (wind from starboard = boom to port side = starboard tack = white nav lights — green on the starboard side); (2) Take bold avoiding action in ample time (Rule 8); (3) Options: (a) bear away (alter course downwind, away from the approaching vessel); (b) tack (come onto starboard tack — but this takes time and may confuse the other vessel); (c) reduce speed (sheet in sails to spill wind). Most practical: bear away significantly. Rule 12 hierarchy: the rule creates two separate scenarios: (A) Different tacks: port-tack vessel always gives way. Simple, unambiguous. (B) Same tack: windward vessel gives way. So: port-tack to windward gives way to port-tack to leeward (windward rule). Starboard-tack to windward gives way to starboard-tack to leeward (windward rule). Identifying the tack: the tack is determined by which side the wind is coming from. Wind on the PORT side = port tack (boom is on the starboard side). Wind on the STARBOARD side = starboard tack (boom is on the port side). In the dark — Rule 25 sailing vessel lights show: starboard side green, port side red. A vessel on starboard tack (boom to port) will show its PORT side (red) to another vessel approaching from windward — but in this scenario, the approaching vessel is to windward, so you see their lights from their side. "Windward vessel always gives way" (option B): this only applies when both vessels are on the SAME TACK. On different tacks, Rule 12(a)(i) applies (port-tack gives way), regardless of which is to windward or leeward. Rule 15 in sailing (option C): Rule 15 (crossing situation) applies to power-driven vessels. For two sailing vessels, Rule 12 governs. Rule 15 does not apply between sailing vessels — they use Rule 12. Starting the engine (option D): a sailing vessel that starts its engine becomes a power-driven vessel for COLREG purposes (Rule 25(b)). This changes its navigation lights and its status in the hierarchy. Starting the engine as a collision avoidance measure may be justified in extremis, but it should be a last resort, and the vessel must then switch to power-driven vessel lights (masthead, sidelights, stern — remove sailing vessel identification).

Question 2

As Chief Mate on watch in open sea, you detect a vessel 10nm ahead with zero CPA and TCPA 30 minutes. Describe the characteristics of a proper avoiding action under Rule 8.

Accepted Answer

RULE 8 — CHARACTERISTICS OF PROPER AVOIDING ACTION: RULE 8 APPLIES TO ALL VESSELS in a potential collision situation, regardless of which rules govern the encounter (crossing, overtaking, head-on). The characteristics: (1) EARLY: action taken in ample time — not waiting until close quarters. With 30 minutes to CPA and 10nm, early action is available. Rule 8(a): action shall be taken "in ample time"; (2) BOLD AND SUBSTANTIAL: Rule 8(b): action shall be "large enough to be readily apparent to the other vessel observing visually or by radar." Small incremental alterations (5° at a time) do not meet this standard. The other vessel must be able to see a CLEAR alteration on their radar; (3) POSITIVE: not just an alteration but a committed and maintained course to the clear; (4) RESULT IN PASSING AT A SAFE DISTANCE: Rule 8(d): the action must result in passing at a safe distance. A 0.5nm CPA in busy waters may be adequate; in open ocean — some companies require 2nm minimum CPA; (5) MAINTAIN THE ALTERATION: do not return to the original course until clearly past and clear; (6) AVOID DANGEROUS COMBINATIONS: Rule 8(c): if necessary to avoid collision or to allow more time — reduce speed or take all way off. Speed reduction alone or combined with course alteration is a valid manoeuvre; SPECIFIC CASE (0 CPA, 30 min): Give way vessel should alter significantly to starboard (if crossing, overtaking, or head-on) — aim for CPA of at least 1-2nm and confirm on radar before resuming original course; (7) RULE 8(e): "necessary to pass at a safe distance". The "5° is not enough" principle: Rule 8(b) specifically requires that course alterations be "large enough to be readily apparent to the other vessel observing visually or by radar." On radar, a 5° alteration is extremely difficult to distinguish from normal navigation variability over 30 minutes. A 30° starboard alteration is clearly visible as a bearing change on the other vessel's radar display. The rule of thumb: 30° alteration produces about 0.5nm change in CPA per mile of range. Radar detection of alteration: an observer on the other vessel watching the radar will see a clear change in the bearing trend if a substantial alteration is made. If the alteration is too small to detect, the other vessel will not know you are taking action — close-quarters will still develop. This is the purpose of the "bold and substantial" requirement. MAIB investigation of Rule 8: several MAIB collision reports have identified that the give-way vessel made "insufficient" alterations — the alteration was made but was too small to be effective or apparent. The avoiding vessel felt they had taken action; the other vessel was unaware of any action and continued on course. Five short blasts (option D): the five short blasts is the DANGER/DOUBT signal (Rule 34(d)) — it expresses doubt about the other vessel's intentions or signals that a vessel does not understand what another is doing. It is NOT a substitute for collision avoidance manoeuvring. Sounding five short blasts while maintaining course is useless for collision avoidance if no other action is taken.

Question 3

In a crossing situation, you are the stand-on vessel. The give-way vessel has not altered course despite your close approach. At what point and how do you act?

Accepted Answer

STAND-ON VESSEL OBLIGATIONS — RULES 16 AND 17: RULE 17 — INITIAL DUTY: the stand-on vessel shall "maintain her course and speed" to allow the give-way vessel to take action. This stability of action allows the give-way vessel to predict the stand-on vessel's position. RULE 17(a)(ii) — MAY ACT: when it becomes APPARENT that the give-way vessel is not taking appropriate action — the stand-on vessel "may take action to avoid collision by her manoeuvre alone." This is a PERMISSION — not yet an obligation. This trigger point is a matter of professional judgement — typically when the stand-on vessel can see that the give-way vessel has not altered AND CPA is becoming dangerously small. RULE 17(b) — MUST ACT: when the stand-on vessel determines that collision "cannot be avoided by the action of the giving way vessel alone" — the stand-on vessel "shall take such action as will best aid to avoid collision." This is the MANDATORY action trigger. At this point — the stand-on vessel MUST act. The action must be: (a) not an alteration to port for a vessel on the port side (Rule 17(c)); (b) bold and substantial; (c) early enough to be effective. SEQUENCE IN THIS SCENARIO: (1) Monitor CPA trend; (2) Sound danger signal (Rule 34(d)) when doubt exists; (3) If no response — consider taking avoiding action under Rule 17(a)(ii); (4) When collision cannot be avoided by give-way alone — MUST act under Rule 17(b); (5) Do NOT turn to port toward a vessel on your port side (Rule 17(c)). Rule 17(c) — no alteration to port: this is one of the most important specific constraints in the COLREGs. In a crossing situation where the give-way vessel is on the STARBOARD side of the stand-on vessel (approaching from starboard) — the stand-on vessel must NOT alter to PORT. Altering to port would swing the stand-on vessel's bow toward the approaching give-way vessel — potentially making the collision more severe. The stand-on vessel's primary avoiding action in a crossing situation where the give-way is to starboard: STARBOARD alteration or SPEED REDUCTION (both swing the bow away from the approaching vessel or create more time/distance). Rule 17(b) as a legal obligation: once the stand-on vessel determines that the give-way vessel cannot alone prevent collision — Rule 17(b) makes action MANDATORY. A stand-on vessel that maintains course and speed into a certain collision because "it was my right of way" is in violation of Rule 17(b). Courts have held both vessels equally negligent in collisions where the stand-on vessel failed to take action under Rule 17(b). "Never alter until collision" (option B): Rule 17 explicitly states the stand-on vessel "may" and eventually "shall" take action. The rule was designed with exactly this scenario in mind — a give-way vessel that fails to act. Blind adherence to course/speed into a certain collision is not professional seamanship and is a COLREG violation under Rule 17(b). Sound signal and alter (option C): sounding one short blast signals an intention to alter to STARBOARD (Rule 34(a)). This is appropriate IF the stand-on vessel is altering to starboard. However, sounding one short blast without actually altering, or altering to port while sounding one blast, is a misuse of the sound signal. The signal should reflect the actual manoeuvre.