Study Guide for the International Regulations for Preventing Collisions at Sea, 1972 (COLREGs)

Short Answer Quiz

Instructions: Answer the following ten questions in two to three sentences each, based on the provided COLREGs text.

1. According to Rule 2, what is the fundamental principle of responsibility for a vessel, its master, and crew?

2. List five of the six factors that must be taken into account by all vessels when determining a "safe speed" under Rule 6.

3. How is a "risk of collision" to be determined, and what assumption must be made if there is any doubt?

4. Describe an "overtaking" situation as defined by Rule 13. What is the primary responsibility of the overtaking vessel?

5. In a "crossing situation" between two power-driven vessels, which vessel is the give-way vessel, and what action should it take?

6. Under what circumstances may the "stand-on" vessel take action to avoid a collision, and what action should it avoid if the other vessel is on its port side?

7. What is the hierarchy of responsibility between a power-driven vessel, a sailing vessel, a vessel engaged in fishing, and a vessel restricted in her ability to manoeuvre?

8. What lights and day shapes must be exhibited by a vessel "not under command" when it is making way through the water?

9. When in sight of one another, what do the following whistle signals mean: one short blast, two short blasts, and five or more short and rapid blasts?

10. What sound signal is required for a power-driven vessel making way through the water in or near an area of restricted visibility?

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Quiz Answer Key

1. Rule 2 states that nothing in the Rules shall exonerate any vessel, or its owner, master, or crew, from the consequences of any neglect to comply with the Rules. It also emphasizes that mariners must take any precaution required by the ordinary practice of seamen or the special circumstances of the case, which may necessitate a departure from the Rules to avoid immediate danger.

2. The factors for determining a safe speed for all vessels include: the state of visibility; traffic density; the vessel's manoeuvrability (stopping distance and turning ability); the presence of background light at night; the state of wind, sea, and current, and proximity of navigational hazards; and the draught in relation to available water depth.

3. A risk of collision must be determined using all available means appropriate to the circumstances, including radar if fitted. If the compass bearing of an approaching vessel does not appreciably change, a risk shall be deemed to exist. If there is any doubt whatsoever, the risk of collision must be assumed to exist.

4. An overtaking situation exists when a vessel approaches another from a direction more than 22.5 degrees abaft her beam. The primary responsibility of the overtaking vessel is to keep out of the way of the vessel being overtaken until it is finally past and clear, regardless of any subsequent change in bearing.

5. In a crossing situation, the vessel which has the other on her own starboard side is the give-way vessel. This vessel must take early and substantial action to keep well clear and, if circumstances admit, shall avoid crossing ahead of the other vessel.

6. The stand-on vessel may take action as soon as it becomes apparent that the give-way vessel is not taking appropriate action. If the situation becomes so close that the give-way vessel's action alone cannot avoid collision, the stand-on vessel must take action. When taking action, a power-driven stand-on vessel shall not alter course to port for a vessel on her own port side.

7. According to Rule 18, a power-driven vessel underway must keep out of the way of a sailing vessel, a vessel engaged in fishing, and a vessel restricted in her ability to manoeuvre. A sailing vessel must keep out of the way of a vessel engaged in fishing and a vessel restricted in her ability to manoeuvre. A vessel engaged in fishing must, so far as possible, keep out of the way of a vessel restricted in her ability to manoeuvre.

8. A vessel "not under command" making way through the water must exhibit two all-round red lights in a vertical line where they can best be seen. In addition to these lights, it must also exhibit sidelights and a sternlight. The corresponding day shapes are two balls in a vertical line.

9. One short blast means "I am altering my course to starboard." Two short blasts mean "I am altering my course to port." At least five short and rapid blasts indicate that a vessel is in doubt about the intentions or actions of another vessel or whether sufficient action is being taken to avoid collision.

10. In or near restricted visibility, a power-driven vessel making way through the water must sound one prolonged blast at intervals of not more than two minutes. A prolonged blast is defined as a blast of four to six seconds' duration.

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Oral Examination Questions

1. Explain the concept of maintaining a "proper look-out" as required by Rule 5. What means should be employed?

2. You are on a power-driven vessel navigating in a narrow channel. What are your obligations regarding positioning and what precautions must you take when nearing a bend?

3. Describe a "head-on situation" between two power-driven vessels. What actions are required by both vessels to ensure safe passage?

4. You are the officer of the watch on a power-driven vessel. In restricted visibility, you detect a vessel by radar alone forward of your beam. A risk of collision is determined to exist. What action must you take regarding your speed, and what alterations of course should you avoid?

5. What is the difference in definition, lights, and shapes between a "vessel not under command" and a "vessel restricted in her ability to manoeuvre"?

6. Describe the lights and day shapes for a vessel aground. What sound signals must this vessel make in restricted visibility?

7. Explain the responsibilities and actions required for both vessels when one vessel intends to overtake another in a narrow channel where the overtaken vessel must take action to permit safe passing.

8. What lights are exhibited by a pilot vessel when on pilotage duty, both when underway and when at anchor? What lights does it show when not on duty?

9. Describe the lights and shapes for a vessel engaged in trawling and for a vessel engaged in fishing other than trawling. When do these vessels also show sidelights and a sternlight?

10. What are the general obligations of a seaplane on the water with respect to other vessels?

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Glossary of Key Terms

Term

Definition

All-round light

A light showing an unbroken light over an arc of the horizon of 360 degrees. (Rule 21)

Flashing light

A light flashing at regular intervals at a frequency of 120 flashes or more per minute. (Rule 21)

Give-way vessel

A vessel which is directed by the Rules to keep out of the way of another vessel. It must, so far as possible, take early and substantial action to keep well clear. (Rule 16)

Length and Breadth

A vessel's length overall and greatest breadth. (Rule 3)

Look-out

A proper watch maintained at all times by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions to make a full appraisal of the situation and risk of collision. (Rule 5)

Masthead light

A white light placed over the fore and aft centreline of the vessel showing an unbroken light over an arc of the horizon of 225 degrees, from right ahead to 22.5 degrees abaft the beam on either side. (Rule 21)

Power-driven vessel

Any vessel propelled by machinery. (Rule 3)

Prolonged blast

A blast of from four to six seconds' duration. (Rule 32)

Restricted visibility

Any condition in which visibility is restricted by fog, mist, falling snow, heavy rainstorms, sandstorms or any other similar causes. (Rule 3)

Sailing vessel

Any vessel under sail provided that propelling machinery, if fitted, is not being used. (Rule 3)

Seaplane

Any aircraft designed to manoeuvre on the water. (Rule 3)

Short blast

A blast of about one second's duration. (Rule 32)

Sidelights

A green light on the starboard side and a red light on the port side, each showing an unbroken light over an arc of the horizon of 112.5 degrees from right ahead to 22.5 degrees abaft the beam on its respective side. (Rule 21)

Stand-on vessel

A vessel that, in a situation where another vessel must keep out of the way, is required to keep her course and speed. (Rule 17)

Sternlight

A white light placed as nearly as practicable at the stern showing an unbroken light over an arc of the horizon of 135 degrees, fixed to show 67.5 degrees from right aft on each side of the vessel. (Rule 21)

Towing light

A yellow light having the same characteristics as the sternlight (unbroken light over an arc of 135 degrees). (Rule 21)

Underway

A vessel that is not at anchor, or made fast to the shore, or aground. (Rule 3)

Vessel

Every description of water craft, including non-displacement craft, WIG craft, and seaplanes, used or capable of being used as a means of transportation on water. (Rule 3)

Vessel constrained by her draught

A power-driven vessel which because of her draught in relation to the available depth and width of navigable water is severely restricted in her ability to deviate from the course she is following. (Rule 3)

Vessel engaged in fishing

Any vessel fishing with nets, lines, trawls or other fishing apparatus which restrict manoeuvrability. It does not include a vessel fishing with trolling lines or other apparatus which do not restrict manoeuvrability. (Rule 3)

Vessel not under command

A vessel which through some exceptional circumstance is unable to manoeuvre as required by these Rules and is therefore unable to keep out of the way of another vessel. (Rule 3)

Vessel restricted in her ability to manoeuvre

A vessel which from the nature of her work is restricted in her ability to manoeuvre as required by these Rules and is therefore unable to keep out of the way of another vessel. (Rule 3)

Whistle

Any sound signalling appliance capable of producing the prescribed blasts and which complies with the specifications in Annex III. (Rule 32)

Wing-In-Ground (WIG) craft

A multimodal craft which, in its main operational mode, flies in close proximity to the surface by utilizing surface-effect action. (Rule 3)