Question 1

You are a Chief Mate on a power-driven vessel in open sea. You observe: a vessel showing red-white-red lights (vertically) to your starboard, and a vessel showing green-white-green lights to your port. What are these vessels and what are your obligations?

Accepted Answer

RULE 18 HIERARCHY — PRACTICAL APPLICATION: STARBOARD VESSEL — RED-WHITE-RED (THREE LIGHTS): Rule 27(b)(i): "A vessel restricted in her ability to manoeuvre... shall exhibit, where they can best be seen: three all-round lights in a vertical line... the highest and lowest of these lights shall be red and the middle light shall be white." RED-WHITE-RED (vertically) = VESSEL RESTRICTED IN ABILITY TO MANOEUVRE (RAM). Rule 27(b)(d) also indicates RAM vessels not making way show only the three lights, without sidelights/masthead lights. PORT VESSEL — GREEN-WHITE-GREEN (THREE LIGHTS): Rule 27(b)(iii): when making way through the water, in addition to the lights in Rule 27(b)(i), RAM vessels show sidelights and a sternlight. A vessel showing green-white-green: (a) Check if this is additional sidelights from a RAM vessel making way (sidelights would add); (b) OR this could be: three all-round GREEN lights — this is typically associated with a government vessel or specific national signals, NOT a standard COLREG light. Actually from the COLREG perspective: THREE GREEN vertical = specific trawling signals in some countries. Need more context. If assuming COLREG context: investigate further. OBLIGATIONS FOR YOUR POWER-DRIVEN VESSEL: Rule 18 hierarchy: vessels give way to (in descending priority): (1) NUC; (2) RAM; (3) CBD; (4) Fishing; (5) Sailing; (6) Power-driven. YOUR OBLIGATIONS: give way to BOTH vessels if they are higher in the hierarchy than a power-driven vessel. RAM vessel to starboard — GIVE WAY. Investigate the green-white-green vessel further before determining obligations. RAM vs NUC light distinction: the critical difference: NUC = two ALL-ROUND RED lights (just red-red). RAM = three lights: red-WHITE-red (red-white-red). The white middle light distinguishes RAM from NUC. If you see only two red lights = NUC. If you see three lights with a white middle = RAM. Red-white-red in distress (option C): distress signals are listed in SOLAS V Annex IV. They include: repeated blasts on fog signal, NC signal (International Code), orange smoke, etc. Three vertical lights (red-white-red) is NOT in the distress signal list — it is the RAM signal. Confusing RAM for distress would trigger a MAYDAY response for a vessel that may be perfectly safe (just restricted in manoeuvring, e.g., a cable laying vessel, dredger, survey vessel). Power-driven gives way to all (option D): not entirely correct. A power-driven vessel is the LOWEST in the Rule 18 hierarchy — so it gives way to NUC, RAM, CBD, fishing, and sailing. However — a power-driven vessel does NOT give way to another power-driven vessel through Rule 18. The crossing/overtaking/head-on rules (Rules 14-17) determine who gives way between two power-driven vessels. Three green lights: in COLREG context, three green lights in a vertical line is not a defined signal in the main Rules. In some national codes, it may represent specific vessel types. A professional OOW would: (a) not assume it is a standard COLREG signal; (b) investigate using radar, AIS, binoculars before determining obligations; (c) apply the "all available means" principle of Rule 7 to assess if a risk of collision exists.

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.