Buoys and lights tell you where the safe water is. In flotilla waters you meet a small set of them: the red and green sides of a channel, the black and yellow cardinals, a few marks that stand alone and the harbour lights.
Which side do I leave a green buoy on when leaving harbour?
To port: in IALA Region A, Europe and the Mediterranean, green is left to starboard coming in from sea, and going out everything swaps. Where there is no obvious way in, a chart arrow shows the direction of buoyage.
Lateral marks show the edges of a channel. They are laid for a boat coming in from the sea. In IALA Region A, which covers Europe and the Mediterranean, you leave red marks to port and green marks to starboard on the way in. The shape says the same: a red can, a green cone.
Going out to sea everything swaps: red stays to starboard, green to port. In a strait between islands there is no "in", so the chart shows the direction of buoyage with an arrow, and you treat that direction as coming in. Heading against it, you leave a green cone to port.
Region B, the Americas and with them the Caribbean, reverses the colours: coming in, red is left to starboard. The shapes keep their sides: can to port, cone to starboard.
Region A, coming in from the sea: red to port, green to starboard. Going out: the other way round.
Where do I steer between the red and green harbour lights at night?
Between them, keeping red to port and green to starboard as you come in. A red light on your starboard bow means you are on the wrong side of it, outside the channel: turn until it is on your port side.
At night the sides keep their colours. Most small harbours show just two lights, a red and a green, one on each pierhead. Coming in, steer between them with the red to port and the green to starboard.
A red light on your starboard bow as you come in means you are on the wrong side of it, outside the channel: turn until it is on your port side. Leaving harbour, the red lights pass down your starboard side.
Which side do I pass a west cardinal buoy on?
On its west side: a cardinal mark is named after the side where the safe water is, so the danger lies east of a west cardinal. At night it shows nine quick white flashes, like nine on a clock face.
A cardinal mark stands beside a danger and is named after the side where the safe water is: pass north of a north cardinal, east of an east one. The danger lies on the opposite side: a west cardinal has its reef to the east. All four are black and yellow, with two black cones on top.
At night the light is white and counts like a clock face: three quick flashes for east, six for south, nine for west, quick flashes without a break for north. The south cardinal adds one long flash, which sets it apart from three and nine.
Turn the compass side into a side of your boat. Heading east towards a north cardinal, north is to port: turn to port and leave the mark to starboard. Never pass between a north and a south cardinal that guard the same danger.
The cones point to the black: up for north, down for south, apart for east, together for west.
What does a yellow buoy with an X on top mean?
It is a special mark: it shows an area, not a danger to steer round. A line of them off a beach is usually the limit of a bathing zone; the chart or pilot book says what they are for.
An isolated danger mark sits on a small danger with navigable water all round: black with a red band, two black balls on top. Pass either side, but give it a good berth. A safe water mark is the opposite: red and white stripes and a red ball mean deep water all round, often at the start of a fairway.
Yellow special marks with an X on top show an area, not a danger to steer round. A line of them off a beach is usually the limit of a bathing zone; the chart or the pilot book tells you what they are for.
What does Fl(3) G 10s mean on a chart?
A green light flashing in groups of three, the whole pattern repeating every 10 seconds. The period is the full cycle, light and dark together; with no colour letter the light would be white.
The chart and the pilot book give every light a short code, so that you can tell it from its neighbours with a watch. Fl(3) G 10s reads: flashes in groups of three, green, the whole pattern repeating every 10 seconds. The period is the full cycle, light and dark together. No colour letter means a white light.
| Code | What you see |
|---|---|
| F | Fixed: a steady light |
| Fl · Fl(2) | Flashing: single flashes · groups of two; more dark than light |
| LFl | A long flash, 2 seconds or more |
| Oc | Occulting: more light than dark |
| Iso | Isophase: light and dark equal |
| Q · VQ | Quick, about one flash a second · very quick, about two |
Time a light that is on for 4 seconds and off for 2, and you have Oc 6s. A buoy marked just Q shows white quick flashes without a break: a north cardinal.
A sector light shows white over the safe approach and red or green over the dangers to either side. If the white turns to a colour as you come in, you have left the safe sector: check the chart and get back into the white.
Questions from this topic, as the app asks them. Open one to see the answer.
Entering Argostoli from the sea, you pass this buoy. On which side do you leave it?
A. On your port side
Region A: a red can marks the port side of the channel going in.
Entering an unfamiliar harbour at night, you see these lights on the pierheads. Where do you steer?
C. Between them: red to port, green to starboard
Region A: the red light marks the port side going in, the green the starboard side.
You see this mark off a headland. Where is the safe water?
B. To the north of it
North cardinal: both cones point up; pass to the north of it.
Off a point near Sivota you see this mark. How do you pass it?
B. Either side, giving it a good berth
Isolated danger: a small danger with navigable water all round — keep well off.
Coming in on the safe white sector of this light, you see it change. What does it mean?
D. You have left the safe sector — check the chart
A sector light shows white over the safe approach; a coloured sector means you are off the line.
Approaching Lefkas at night, you see a white light: six quick flashes, then one long flash. Where do you pass the mark?
C. To the south of it
Q(6)+LFl is a south cardinal; the long flash tells it apart from Q(3) and Q(9).
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