Back to modulesCourse overview

IALA A Buoyage revision module 3 of 5

CARD

Cardinal Marks and Flash Rhythms

North, east, south, and west cardinal marks with colour bands, topmarks, safe side, and quick-flash rhythm memory.

north cardinaleast cardinal

8 guided lessons · 10 practice questions · 10 flashcards

3 outcomes · self-guided revision
  • State the named compass side on which safer water lies relative to a cardinal mark's point of interest, then identify what the current chart and vessel plan must still establish.
  • Relate the named north, east, south and west cardinal quadrants to true bearings from a point of interest without turning quadrant geometry into an uncharted steering sector.
  • Identify all four cardinal marks by combining double-cone orientation and black-and-yellow band order, including the limits of body shape and topmark availability.

A self-guided revision companion that explains essential concepts, then helps you practise and test them. It supports—but does not replace—recognised instruction, practical training, assessment or certification. Access is a one-time payment, not a subscription.

More ways to revise
Lesson previewWhat A Cardinal Mark Says1 section shown

Preview lesson

What A Cardinal Mark Says

The cardinal name is an instruction about relationship. Safer navigable water lies north of a north cardinal, east of an east cardinal, south of a south cardinal and west of a west cardinal. The reference is the compass, not the side of the vessel or its present heading.

IALA describes the relationship to a point of interest. That point may be a shoal, wreck, obstruction, end of a shoal, bend, junction or fork. The current chart shows what is being marked and how the cardinal fits the surrounding route; the buoy alone cannot draw the danger's full outline.

The named side is the side on which the mark should be passed for the stated relationship. It is not an instruction to pass close, a promise of uniform depth or proof that every other compass side is unusable. IALA notes, for example, that a north cardinal can have navigable water east and west as well; consult the relevant chart.

Turn recognition into a vessel decision by checking position, danger extent, soundings, tide or water level where relevant, traffic, weather, local directions and an adequate margin. A correct mark name is the start of that decision, not its completion.

Mark nameGoverning relationshipStill establish from the navigation picture
North cardinal markPass north of the mark; safe water lies to the north.Point of interest, danger extent, usable depth, traffic and vessel margin
East cardinal markPass east of the mark; safe water lies to the east.Point of interest, danger extent, usable depth, traffic and vessel margin
South cardinal markPass south of the mark; safe water lies to the south.Point of interest, danger extent, usable depth, traffic and vessel margin
West cardinal markPass west of the mark; safe water lies to the west.Point of interest, danger extent, usable depth, traffic and vessel margin

Optional quick check

Section 1 of 1

A north cardinal is correctly identified. Which statement turns that identification into a safe planning step?

Choose one answer
Continue to Practise

Full IALA A Buoyage revision access

Get every teaching section, guided practice set, topic test, one-card-at-a-time flashcard, and the full revision path.