IALA

Practical guides to the COLREGS, buoyage, lights and shapes, and exam prep - written to be useful at the chart table, not just in the classroom.

BuoyageIALANavigation

IALA Buoyage Regions A and B: what actually changes

Lateral marks swap colours between IALA Region A and Region B - cardinal, safe water, isolated danger and special marks do not. Here is the difference that matters, and how to keep it straight.

2 June 2026 · 2 min read