SVOP Collision Avoidance and Regulations 2 — Questions and Answers

Question 1: Rule 9 of the Collision Regulations requires vessels in a narrow channel to:

Keep to the starboard side of the channel as far as practicable (Correct answer)
Keep to the port side and flash a light signal when meeting traffic
Anchor and wait for oncoming traffic to clear before proceeding
Travel down the centre of the channel at reduced speed

Correct answer: Keep to the starboard side of the channel as far as practicable

Rule 9 states that vessels proceeding along a narrow channel or fairway shall keep as near to the outer limit on the starboard (right) side as is safe and practicable, just like driving on the right side of a road.

COLREGS Rule 9 (Narrow Channels) is one of the foundational rules in collision avoidance. Keeping to starboard in a narrow channel allows orderly two-way traffic in a restricted fairway. The rule also states that a vessel shall not cross a narrow channel if doing so impedes the passage of a vessel that can only safely navigate within the channel. Small vessels are specifically warned not to impede power-driven vessels or sailing vessels in narrow channels. A vessel of less than 20 metres or a sailing vessel shall not impede the passage of a vessel that can only navigate safely within a narrow channel or fairway.

Question 2: What does a single prolonged blast (4–6 seconds) on a vessel's whistle signal in fog?

A power-driven vessel making way through the water (Correct answer)
A vessel at anchor in restricted visibility
A vessel in distress needing assistance
A vessel aground and warning off other traffic

Correct answer: A power-driven vessel making way through the water

Rule 35(a) requires a power-driven vessel making way in restricted visibility to sound one prolonged blast at intervals of not more than 2 minutes. This signals the vessel is underway and moving through the water.

COLREGS Rule 35 specifies fog signals for different vessel types and situations. A power-driven vessel making way (propulsion engaged, moving through the water) sounds one prolonged blast every 2 minutes. A power-driven vessel underway but stopped (engines running but not making way) sounds two prolonged blasts with about 2 seconds between them, every 2 minutes. A vessel at anchor sounds a rapid bell ringing for about 5 seconds every minute. A vessel aground sounds three strokes of the bell (rap-rap-rap) before and after the bell ringing. Knowing these signals is critical for navigating safely in restricted visibility.

Question 3: When two sailing vessels are approaching each other and both have the wind on the same side, which vessel gives way?

The vessel to windward gives way to the vessel to leeward (Correct answer)
The larger vessel gives way regardless of wind position
The vessel travelling faster gives way
The vessel to leeward gives way to the vessel to windward

Correct answer: The vessel to windward gives way to the vessel to leeward

COLREGS Rule 12(a)(ii): when two sailing vessels have the wind on the same side, the vessel to windward (closer to the direction the wind is coming from) shall give way to the vessel to leeward (further from the wind direction).

Rule 12 governs sailing vessel encounters. When two sailing vessels are approaching one another: (1) if on opposite tacks, the vessel on port tack gives way to the vessel on starboard tack; (2) if on the same tack, the vessel to windward gives way to the vessel to leeward; (3) if a vessel on port tack sees a vessel to windward and cannot determine whether it is on port or starboard tack, the port tack vessel gives way. These rules exist because the leeward vessel has less manoeuvrability (the windward vessel's sails are not blanketing it), and the windward vessel can bear away more easily to avoid a collision.

Question 4: What action is the 'give-way' vessel required to take under the Collision Regulations?

Take early and substantial action to keep well clear, avoiding crossing ahead of the stand-on vessel (Correct answer)
Wait until the last possible moment before altering course
Flash a light signal and hold course unless collision is imminent
Sound a whistle and slow to dead stop

Correct answer: Take early and substantial action to keep well clear, avoiding crossing ahead of the stand-on vessel

Rule 16 requires the give-way vessel to take early and substantial action to keep well clear. 'Early' means with sufficient time, not last-minute; 'substantial' means a clearly visible course or speed change, not a small adjustment.

Rule 16 (Action by Give-Way Vessel) is clear: the give-way vessel shall, so far as possible, take early and substantial action to keep well clear. 'Early' ensures the stand-on vessel can observe the action and confirm it is working. 'Substantial' means a course alteration large enough to be evident on the other vessel's radar or visually — ideally 30 degrees or more, or a significant reduction in speed. A small, late course change is insufficient and can lead to confusion and collision. The give-way vessel must not only alter course but must monitor the situation until safely past and clear.

Question 5: Under Rule 17, when may the stand-on vessel deviate from its course and speed?

When it becomes apparent that the give-way vessel is not taking sufficient action to avoid collision (Correct answer)
At any time — the stand-on vessel always has priority and can manoeuvre freely
Only after sounding five short blasts and waiting 30 seconds
Only if directed to do so by a Vessel Traffic Service

Correct answer: When it becomes apparent that the give-way vessel is not taking sufficient action to avoid collision

Rule 17(a)(ii) allows the stand-on vessel to take action to avoid collision by its own manoeuvre when it becomes apparent the give-way vessel is not acting. Rule 17(b) requires action when collision cannot be avoided by the give-way vessel alone.

Rule 17 establishes the obligations of the stand-on vessel. Initially, the stand-on vessel must maintain course and speed. However, the rule contains two important exceptions: (1) when it becomes apparent that the give-way vessel is not taking appropriate action, the stand-on vessel may take action on its own (Rule 17(a)(ii)); and (2) when collision cannot be avoided solely by the give-way vessel, the stand-on vessel must take the best action possible (Rule 17(b)). In all cases, the stand-on vessel should avoid turning to port for a vessel to port (Rule 17(c)). The rules create a hierarchy of responsibility but ultimately both vessels must act to prevent collision.

Question 6: What is the meaning of five or more short blasts on a vessel's whistle?

Danger signal — the vessel is unsure of the other vessel's intentions or believes a collision is imminent (Correct answer)
The vessel is departing a berth and requests others to keep clear
An overtaking vessel requesting permission to pass on the port side
A vessel at anchor warning of its position in fog

Correct answer: Danger signal — the vessel is unsure of the other vessel's intentions or believes a collision is imminent

Five or more short blasts is the doubt or danger signal under Rule 34(d). It means the vessel is in doubt about the other's intentions or actions, or that a collision risk exists and immediate action is required.

Rule 34(d) of the Collision Regulations states: when vessels are in sight of one another and either fails to understand the intentions or actions of the other, or doubts whether sufficient action is being taken to avoid collision, the vessel in doubt shall indicate this by sounding at least five short and rapid blasts. This is also called the 'danger signal' or 'in doubt signal'. It is not a signal meaning 'stop' — it is a warning to the other vessel that the situation is uncertain. Upon hearing it, both vessels should immediately reduce speed, sound a response, and take avoiding action as appropriate. It is also used when a vessel disagrees with a proposed passing arrangement.

SVOP Collision Avoidance and Regulations 2

Rule 9 of the Collision Regulations requires vessels in a narrow channel to: