Red, green, black and yellow

What to look for

• Two pieces of context come first

  Confirm Region A or B and the charted conventional direction of buoyage. Lateral shape identifies the side; lateral colours reverse between the regions.

• A cardinal needs its full identity

  Use the paired cone topmarks, black-and-yellow bands, light and chart together. Its name identifies the side of the mark on which navigable water lies; it does not promise unlimited depth or a route from any starting position.

1. 01

   Lateral marks need context

   Lateral marks identify the sides of a channel. In IALA Region A, a vessel following the conventional direction of buoyage generally keeps red port-hand marks to port and green starboard-hand marks to starboard. Region B reverses the lateral colours. Shape and topmark also identify the side. Confirm the region, direction of buoyage and local charted information before relying on a rhyme.

2. 02

   Cardinal marks point to safe water

   A north cardinal indicates navigable water lies to the north of the mark; the same principle applies south, east and west. Their black-and-yellow bands, paired cone topmarks and white-light rhythms identify them. Learn the complete visual set with the diagram, not from colour alone.

   • North: both cones point up
   • South: both point down
   • East: cones point away
   • West: cones point towards each other

   Learn the light, not only the colour

   Each cardinal mark flashes its real rhythm. The bars under the drawing show the same flashes over 30 seconds.

   North · both cones point upQ · continuous

   East · cones point away from each otherQ(3) every 10 s

   South · both cones point downQ(6)+LFl every 15 s

   West · cones point towards each otherQ(9) every 15 s

   Each bar is 30 seconds. Q = quick flashing, drawn here at 60 flashes a minute. LFl = long flash of at least 2 seconds. Very quick (VQ) versions also exist.

3. 03

   Four more marks to recognise

   Lateral and cardinal marks are only part of the picture. Learn these four too, and check each one against the chart and current navigation information.

   • Isolated danger: Black with red horizontal bands and two black balls as the topmark. The light, when fitted, is white with groups of two flashes. It marks a danger with navigable water around it. Check the chart for the danger’s extent and passing distance; do not head straight for the mark.
   • Safe water: Red and white vertical stripes, with a single red ball topmark where fitted. White light: isophase, occulting, one long flash every ten seconds or Morse A. It indicates navigable water around the mark, often at a fairway or approach. It does not establish a clear route from your present position.
   • Special mark: Yellow, with a yellow X topmark where fitted and a yellow light if lit. Look up the area or feature in the chart and nautical publications. A yellow buoy is not automatically a swimming-area boundary or permission to enter.
   • Emergency wreck mark: Blue and yellow vertical stripes, an upright yellow cross where fitted and an alternating blue/yellow light. Treat it as a warning of a new danger and check current navigation information. Other mark types can also mark new dangers; this buoy is not the only warning you may meet.

   Four more marks to recognise

   Colour, topmark and light together, then the chart.

   • Isolated danger
   • Safe water
   • Special mark
   • Emergency wreck

4. 04

   Know enough to stop a bad call

   A deckhand may support a tender driver or call what is visible from the bow, but should not improvise pilotage. Use current charts and the vessel's navigation information. If a mark does not match your expectation, slow the conversation down and ask. Being unsure for ten seconds is cheaper than an outboard leg.