COLREGs you see, not just recite.

Why it matters in the oral

Every oral comes back to the collision regulations. Reciting a rule is the easy part. The examiner wants to hear what you would see from the bridge, what you would do, and when.

Here the encounters play out in front of you. You judge the risk of collision, decide who gives way, and act on it. Then you answer the questions an examiner asks about that situation.

Oral questions

COLREGs questions, and what a good answer covers.

The most-asked come first. In the course, each one follows the lesson where you have just done it.

1. When must navigation lights be shown?Often asked

   A good answer covers:

   • From sunset to sunrise, in all weathers
   • In restricted visibility, by day as well
   • And at any other time it is thought necessary
   • No other lights that could be mistaken for them, spoil their visibility or distinctive character, or hinder the lookout

   Practised in the lesson Sunset: navigation lights and the evening routine.

2. Describe the lights of an 82 metre power-driven yacht under way, with their arcs and ranges.Often asked

   A good answer covers:

   • Two masthead lights, the after one higher: white, 225 degrees, from right ahead to 22.5 degrees abaft the beam each side
   • Sidelights, red to port and green to starboard: 112.5 degrees each, from right ahead to 22.5 degrees abaft the beam
   • Sternlight: white, 135 degrees, 67.5 degrees each side of right astern
   • 50 metres or more: masthead lights 6 miles; sidelights, sternlight, towing and all-round lights 3 miles
   • The second masthead light is optional under 50 metres, required at 50 metres and over

   Practised in the lesson Sunset: navigation lights and the evening routine.

3. Name as many signals of distress as you can.Often asked

   A good answer covers:

   • A gun or other explosive signal fired at intervals of about a minute
   • A continuous sound with any fog signalling apparatus
   • Rockets or shells throwing red stars, one at a time at short intervals
   • SOS by any signalling method, and MAYDAY spoken by radio
   • The flags N over C, or a square flag with a ball or something like one above or below it
   • Flames on the vessel, a red parachute or hand flare, orange smoke
   • Arms outstretched to each side, slowly and repeatedly raised and lowered
   • A DSC distress alert, EPIRB signals, SART signals, and a dye marker

   Practised in the lesson Signals: flags and distress signals.

4. What do flags A, D, G, H, O and V mean?Often asked

   A good answer covers:

   • A: I have a diver down; keep well clear at slow speed
   • D: keep clear of me; I am manoeuvring with difficulty
   • G: I require a pilot (H: I have a pilot on board)
   • O: man overboard
   • V: I require assistance (W: I require medical assistance)

   Practised in the lesson Signals: flags and distress signals.

5. From the bridge you see orange smoke on the bow. Take me through what you do.Often asked

   A good answer covers:

   • Note the time, the bearing and range if known, and our own position, at once
   • Call the master
   • Listen on VHF 16, watch the DSC, and try to raise the vessel
   • Tell the coast station or the rescue coordination centre what was seen, where and when
   • Proceed to assist unless the master decides it is unreasonable or unnecessary; extra lookouts and rescue gear ready
   • Record it all in the deck log

   Practised in the lesson Signals: flags and distress signals.

6. You see a light on the bow at night. How do you identify it?Often asked

   A good answer covers:

   • Note its colour and time its characteristic over several periods with a stopwatch
   • Take its bearing, and estimate where it should be from the DR or the last fix
   • Look for lights of that characteristic near that bearing on the chart and in the List of Lights
   • Check the sector, the elevation and the range: could it be seen from here at all?
   • Never identify a light on its characteristic alone where two lights share it

   Practised in the lesson Identifying lights at night, and fixing on them.

7. Explain these characteristics: Fl(2) 10s, Oc 4s, Iso 6s, Q, and Mo(A).Often asked

   A good answer covers:

   • Fl(2) 10s: groups of two flashes, the whole pattern repeating every 10 seconds
   • Oc 4s: occulting, light longer than dark, eclipsed once every 4 seconds
   • Iso 6s: isophase, equal light and dark, the period 6 seconds
   • Mo(A): Morse code A, a short then a long, often used on safe water marks

   Practised in the lesson Identifying lights at night, and fixing on them.

8. You are the stand-on vessel and the give-way vessel is not taking action. What do you do, and when?Often asked

   A good answer covers:

   • Rule 17(a)(i): keep your course and speed at first
   • Sound at least five short and rapid blasts as soon as it is in doubt that she is taking enough action (Rule 34(d)), and you may add a light signal
   • Rule 17(a)(ii): you may then take action on your own to avoid collision, as soon as it is apparent she is not acting
   • Rule 17(b): when collision cannot be avoided by her action alone, you must take the action that best helps
   • Rule 17(c): for a vessel crossing from your port side, do not alter course to port if you can help it
   • Taking action does not relieve the give-way vessel of her duty to keep out of the way (Rule 17(d))

   Practised in the lesson COLREGs in sight: a give-way ship that does not, then head-on.

9. When is it a head-on situation, and what does each vessel do?Often asked

   A good answer covers:

   • Two power-driven vessels meeting on reciprocal or nearly reciprocal courses, with risk of collision
   • By day you see the other ship ahead or nearly ahead, her masts in line or nearly in line; by night her masthead lights in line and both sidelights
   • When in doubt whether it is head-on, assume it is and act accordingly
   • Each alters course to starboard, so that each passes on the port side of the other
   • Make the alteration early and large enough to be obvious, with one short blast when in sight

   Practised in the lesson COLREGs in sight: a give-way ship that does not, then head-on.

10. When is one vessel overtaking another, and who keeps out of the way?Often asked

    A good answer covers:

    • Coming up with another vessel from more than 22.5 degrees abaft her beam: by night she would see only the sternlight
    • The overtaking vessel keeps out of the way of the one being overtaken, whatever kind of vessel either is
    • In doubt, assume you are overtaking
    • A later change in the bearing does not make it a crossing situation: the duty stays until she is finally past and clear
    • In a narrow channel the overtaking signals of Rule 34(c) apply when the other vessel has to act to allow her to pass

    Practised in the lesson COLREGs in sight: a give-way ship that does not, then head-on.

11. You are on watch and the visibility closes in. What do you do?Often asked

    A good answer covers:

    • Call the master, as the standing orders require
    • Start the right fog signal for the vessel, and keep listening for others
    • Navigation lights on, whatever the time of day
    • Proceed at a safe speed for the conditions, with the engines ready for immediate manoeuvre
    • Hand steering, and post extra lookouts, including one placed to listen
    • Both radars running, targets plotted on ARPA, and the position fixed more often
    • Close watertight doors where fitted, and write it all in the deck log

    Practised in the lesson Restricted visibility: when the fog comes in.

12. Give me the fog signals for a power-driven vessel, a vessel not under command, and a vessel at anchor.Often asked

    A good answer covers:

    • Power-driven making way: one prolonged blast at intervals of not more than two minutes
    • Power-driven under way but stopped: two prolonged blasts in succession, at not more than two minutes
    • Not under command, restricted in her ability to manoeuvre, constrained, sailing, fishing or towing: one prolonged then two short, at not more than two minutes
    • At anchor: the bell rung rapidly for about five seconds at intervals of not more than one minute; at 100 metres or more, the bell forward and then the gong aft

    Practised in the lesson Restricted visibility: when the fog comes in.

13. You detect a vessel by radar alone, forward of the beam and closing. What does Rule 19 say about your action?Often asked

    A good answer covers:

    • Decide whether a close-quarters situation is developing or risk of collision exists
    • If so, take avoiding action in good time
    • Avoid an alteration to port for a vessel forward of the beam, other than one being overtaken
    • Avoid an alteration towards a vessel abeam or abaft the beam
    • The steering and sailing rules for vessels in sight of one another do not apply here: there is no stand-on vessel

    Practised in the lesson Restricted visibility: when the fog comes in.

14. A sidelight fails at night. What do you do?

    A good answer covers:

    • Acknowledge the lamp failure alarm, and switch to the spare lamp or the other circuit at once
    • Check from outside that the light is actually showing
    • If it cannot be restored, rig the emergency or spare light and tell the master
    • Log the failure, the time and what was done, and report the defect

    Practised in the lesson Sunset: navigation lights and the evening routine.

15. A white flare goes up from a fishing vessel crossing ahead of a ship. Is that distress?

    A good answer covers:

    • No. A white flare is used to attract attention or to warn of risk of collision
    • Only the signals in Annex IV mean distress; using anything that could be confused with them otherwise is prohibited
    • Still watch her, and be ready to act if anything changes

    Practised in the lesson Signals: flags and distress signals.

16. How would you recognise the four cardinal marks at night?

    A good answer covers:

    • All show a white light, quick or very quick flashing
    • North: continuous flashing
    • East: groups of three
    • South: groups of six followed by a long flash
    • West: groups of nine
    • Think of a clock face: three, six and nine

    Practised in the lesson Identifying lights at night, and fixing on them.

17. What is the difference between the luminous range, the nominal range and the geographical range of a light?

    A good answer covers:

    • Luminous range: how far the light can be seen given its intensity and the visibility at the time
    • Geographical range: how far it can be seen over the curve of the earth, from its elevation and the height of eye
    • A light can only be seen at the lesser of the luminous and geographical ranges

    Practised in the lesson Identifying lights at night, and fixing on them.

18. What are the manoeuvring and warning signals for vessels in sight of one another?

    A good answer covers:

    • One short blast: I am altering my course to starboard
    • Two short blasts: I am altering my course to port
    • Three short blasts: I am operating astern propulsion
    • At least five short and rapid blasts: I do not understand your intentions, or doubt you are taking enough action
    • One prolonged blast near a bend or obstruction, answered by one prolonged blast
    • A short blast is about one second, a prolonged blast four to six seconds

    Practised in the lesson COLREGs in sight: a give-way ship that does not, then head-on.

19. What makes action to avoid collision good action under Rule 8?

    A good answer covers:

    • Positive, made in ample time, and in keeping with good seamanship
    • Large enough to be readily apparent to the other vessel by eye or radar: avoid a series of small alterations
    • An alteration of course alone may be best in open water, if made in good time and it does not cause another close-quarters situation
    • It must result in passing at a safe distance; check it until the other vessel is finally past and clear
    • Slow down, stop or go astern if more time is needed

    Practised in the lesson COLREGs in sight: a give-way ship that does not, then head-on.

20. You hear a fog signal apparently forward of the beam, and you cannot see the vessel. What now?

    A good answer covers:

    • Unless you have found that risk of collision does not exist
    • Reduce speed to the minimum at which you can keep your course
    • Take all way off if necessary
    • Navigate with extreme caution until the danger of collision is over

    Practised in the lesson Restricted visibility: when the fog comes in.

21. What decides a safe speed in fog?

    A good answer covers:

    • The visibility, and the traffic density, including fishing vessels
    • How quickly the vessel can stop and turn in the conditions
    • Background light at night, the wind, sea and current, and nearby dangers
    • Draught against the depth of water
    • The radar: its range scale, its limits, small targets lost in clutter, and how many targets it shows
    • A speed at which she can stop within the distance you can see is a good rule of thumb, though the rules give no figure

    Practised in the lesson Restricted visibility: when the fog comes in.

22. What else belongs in an evening routine as the sun goes down?

    A good answer covers:

    • Lights on before sunset and checked, and the deck and accommodation lights not dazzling or confusing
    • Weather observation in the deck log: wind, sea, visibility, pressure and its trend, temperature
    • Wheelhouse lighting down and the radar and ECDIS palettes changed for night vision

    Practised in the lesson Sunset: navigation lights and the evening routine.

Preparing for the OOW 3000 oral? See the whole syllabus, topic by topic. Also: ECDIS and electronic aids.