Planning to take your boat into Canadian waters? Those yellow-and-black striped buoys you'll encounter there follow a system many American boaters have never had to learn — and knowing how to read them could be the difference between safe passage and running aground.

The buoys are called cardinal markers, and they're part of a standardized buoyage system developed by the International Organization for Marine Aids to Navigation (IALA), used worldwide with regional variations. Unlike the red and green channel markers familiar to US boaters — which tell you which side of your vessel to leave the buoy on — cardinal buoys point you toward safe water by compass direction. A south cardinal buoy, for example, means you should pass on the buoy's south side to stay in safe water.

There are four variants, one for each cardinal direction, and each combines a distinct colour scheme, topmark shape, and light pattern:

- **North**: black band over yellow, two black cones pointing up, white light flashing continuously at a quick or very quick rate.
- **South**: yellow over black, two cones pointing down, six quick white flashes followed by one long flash.
- **East**: black with a yellow band, two cones base-to-base, three quick white flashes in groups.
- **West**: yellow with a black band, two cones point-to-point, nine quick white flashes in groups.

A handy memory trick baked into the design: the cone arrangements and flash counts correspond to a clock face — three for east, six (plus a long flash) for south, nine for west.

Why should this matter to holiday-makers? Cardinal buoys are not used in the US Coast Guard's aids-to-navigation system, so boaters whose routes cross into Canada — whether exploring Great Slave Lake, North America's deepest lake, or the Discovery Islands off British Columbia — will meet these markers for the first time on Canadian waters. The system isn't uniquely Canadian either; it's international IALA standard, so the same skills apply to cruising in Europe, Africa, Asia and beyond.

The practical takeaway is simple: before setting out on any boating trip abroad, review the local navigational aids. A few minutes of prep means those striking yellow-and-black buoys become helpful signposts rather than confusing hazards — and they'll keep you in safe water whether you're fishing, island-hopping, or just out for a sunset cruise.

Story via Islands.