1:1 ON YOUR DATE
Buoyage - Cardinal, Lateral and Special Marks - IALA A Buoyage system
IALA = International Association of Lighthouse Authorities. Trinity House ( http://www.trinityhouse.co.uk ) is the authority for the UK, they maintain all the lighthouses and navigation marks.
Pierre Noire West Cardinal Mark
Tide running at 3 knots +
North Cardinal No topmark
Lateral marks - IALA A
Mark a channel, danger or area
The colour of lateral marks may be unclear when the sun is behind them - remember the cone or can shapes.
Mark a danger or indicate which side to pass. On a chart, a vertical mark is fixed, a leaning mark is buoyed and floating.
|Cardinal marks are located to
the North, East, South or West of a hazard - ie the Cardinal Points of the
compass. They each have a distinctive topmark, colour scheme and light
The Top Marks are logical:
North - 2 black cones pointing Up.
East - 2 cones pointing up and down. You can remember this as an Egg.
South - 2 cones pointing Down.
West - 2 cones point to point. Like a Wineglass or Mae West
If the topmarks are missing, the Black and Yellow stripes are distinctive - the top mark cones point to the Black Stripe(s)
The lights are based on the clock face: the lights can be Quick Flash or Very Quick Flash, at 15 sec or 10 sec intervals to avoid confusion with marks close together.
East cardinal is at 3 o'clock - 3 flashes.
South cardinal is at 6 o'clock - 6 flashes - plus a long flash to avoid confusion with a West cardinal. At night it can be difficult to count a large number of flashes, with the waves hiding some.
West cardinal is at 9 o'clock - 9 flashes. So if you see a large number of flashes with no long flash, that is a West Cardinal.
North cardinal at 12 o'clock - In theory 12 flashes, but actually it is continuous flashing. So a large number of flashes with no dark interval is a North Cardinal.
The RNLI has an excellent on line teaching program at: RNLI training program
New wreck buoy For more information see http://www.trinityhouse.co.uk/pdfs/pdf_wreck_buoy.pdf
Moiré Light is used to provide a directional beam: example - a transit for narrow bridge see Moire_light.pdf and Moire light and HAT Vertical clearances
Posted 15th June 2011