Question 1

It is night. You observe a white light flashing in a group of 3 quick flashes, repeating approximately every 10 seconds. The buoy is bearing 090° at 1.2nm. What is this buoy and what action do you take?

Accepted Answer

EAST CARDINAL MARK. Light: Q(3) (3 quick flashes) or VQ(3) white, period 5 or 10 seconds. 3 = East (3 o'clock). The buoy is bearing 090° (due east of you). Meaning: safe water lies to the EAST of this mark — the hazard is to the west of the buoy. You are approaching from the west (the mark is east of you) which means you are approaching the hazard side of the mark. Action: DO NOT continue east towards the mark — there is danger to the west of the mark (and you are approaching from the west, heading east). Alter course to pass the mark to the EAST (keeping the mark to your west as you pass), OR pass to the north or south of the hazard on clearly charted safe water. Immediately check the chart to identify the nature and extent of the hazard the mark is protecting. This scenario specifically tests night identification from light characteristic alone — the most demanding but most realistic scenario because at sea you often detect a light before you can identify a topmark or colour. The east cardinal Q(3) or VQ(3) — three is the key: think "east = 3 o'clock". The approaching scenario is deliberately set up to test whether the candidate recognises they are approaching the WRONG side of the mark (approaching from the west when the safe water is to the east). This is the most dangerous situation with any cardinal mark: approaching from the wrong side means you are heading toward the hazard the mark is protecting. Immediate actions: (1) positively identify the mark from the light characteristic; (2) cross-reference with the chart — what is the marked hazard? shoal? wreck? rock?; (3) determine safe water and alter course accordingly; (4) if the hazard is uncertain, treat the area as dangerous and stand off until the chart confirms the safe route. The OOW exam tests not just identification but the follow-on navigation decision.

Question 2

Your examiner asks: in IALA System A (used in the UK and Europe), a red can buoy is seen to port on the starboard side of a channel. Are you entering or leaving harbour, and on which side do you pass it?

Accepted Answer

IALA System A — Red to PORT when entering harbour (proceeding from seaward). Red can buoy on your port side means you are on the starboard side of the channel, heading seaward (leaving harbour). To re-enter, you would keep the red buoy to PORT. Rule: In IALA A: RED = PORT = entering harbour (coming from sea). Green = Starboard = entering harbour. Memory aid for IALA A: "Red to Port Returning." The question states the red buoy is to port — therefore you are ENTERING HARBOUR correctly, keeping the channel to starboard. Pass the red buoy keeping it to PORT (leave it on your port side). In IALA B (Americas, Japan, Philippines, Korea): colours are reversed — red to starboard entering. IALA System A covers Europe, Africa, India, Australia, and most of Asia. IALA System B covers the Americas, Japan, the Philippines, and South Korea. The fundamental difference is the colour assignment for lateral marks. IALA A: PORT side mark = RED (can or spar shape, red light any rhythm); STARBOARD side mark = GREEN (conical shape, green light any rhythm). IALA B: PORT side mark = GREEN; STARBOARD side mark = RED. The "conventional direction of buoyage" defines port and starboard: in harbour approaches and rivers, it is the direction proceeding from seaward into the harbour/upstream. On coasts, the conventional direction runs clockwise around continents (in the northern hemisphere: north along the east coast, east along the south coast, south along the west coast). A candidate serving on UK vessels must know IALA A thoroughly and understand IALA B for voyages to the Americas. The examiner will use a colour card or verbal description and expect immediate identification of the mark type, meaning, and passing action.

Question 3

On radar you detect a buoy at 358° 0.8nm. As you approach visually you see: two black cones both pointing UP as topmarks; black upper body, yellow lower body; the light characteristic is VQ (very quick flashing — approximately 120 flashes per minute). What is this mark, what does it indicate, and how do you pass it?

Accepted Answer

NORTH CARDINAL MARK. Topmark: two cones BOTH pointing UP (like an arrow pointing north). Colour: black over yellow (black upper, yellow lower). Light: white VQ (very quick) or Q (quick) — uninterrupted. Meaning: safe water lies to the NORTH of this mark. The mark indicates a hazard to its south — the safe side to pass is to the NORTH. Action: pass the mark to the NORTH — i.e., keep the mark to the SOUTH of you as you pass. In this scenario the buoy is bearing 358° (nearly north), so you are approaching from the south — the mark is warning you of danger to your south; you are already in the safe water north of the mark. Monitor: do not pass to the south of this buoy. Cardinal marks are the most systematically tested buoyage topic at OOW level because the examiner can test all four quadrants with slight variations. The cardinal system is based on the compass: the mark indicates the safe water lies in the direction of the compass point named. NORTH cardinal: safe water to the NORTH. SOUTH cardinal: safe to the SOUTH. EAST cardinal: safe to the EAST. WEST cardinal: safe to the WEST. Topmark memory aid: think of the clock face — N = both points UP (12 o'clock, both up); S = both points DOWN (6 o'clock, both down); E = both points OUT (3 o'clock, open to east); W = both points IN (9 o'clock, hourglass shape, like a W). Colour: N = black over yellow (black on top); S = yellow over black (yellow on top); E = black-yellow-black banding; W = yellow-black-yellow banding. Light characteristics (all white): N = VQ or Q (continuous); S = VQ(6)+LFl or Q(6)+LFl (6 quick + long flash — the 6 at the bottom = 6 o'clock = south); E = VQ(3) or Q(3) (3 groups = 3 o'clock = east); W = VQ(9) or Q(9) (9 groups = 9 o'clock = west).