USCG Exam PracticeAids to Navigation — IALA-B (US) buoyage
A mariner accustomed to US waters is now transiting a channel in northern Europe. A red lateral buoy is sighted to starboard. Under IALA-A, what does this indicate?
- A. The vessel is on the starboard side of the channel returning from sea, consistent with IALA-B
- ✓ The red buoy marks the port side of the channel when returning from sea; the vessel should keep it to portCorrect
- C. Red buoys in IALA-A mark the centerline of the fairway
- D. The buoy is a special mark and has no lateral significance
Why B is correct
In IALA-A, port-hand marks are red, the reverse of IALA-B. A red buoy marks the port side of the channel when returning from sea, so it must be kept to port — not starboard as a US mariner might assume.