Lateral Buoyage Practice Questions

1. In U.S. waters (IALA Region B), a red buoy with an even number marks which side of the channel when returning from sea?

• A.Starboard (right) side — keep it to starboard✓
• B.Port (left) side — keep it to port
• C.The center of a safe channel
• D.An isolated danger below the surface

Why: IALA Region B follows 'Red Right Returning.' Red, even-numbered aids mark the starboard side of the channel when proceeding from seaward toward a harbor or upriver.

2. What shape is a standard port-hand lateral buoy in U.S. waters?

• A.Nun (conical)
• B.Can (cylindrical)✓
• C.Sphere
• D.Pillar with topmark

Why: Port-hand (left side when returning) buoys in U.S. waters are green, odd-numbered CAN (cylindrical) buoys. Starboard-hand buoys are red, even-numbered NUN (conical) buoys.

3. Lateral buoy numbers in U.S. waters increase in which direction?

• A.From sea toward the head of navigation✓
• B.From the head of navigation toward the sea
• C.From south to north regardless of channel direction
• D.From east to west along the coastline

Why: Buoy numbers increase from seaward toward the head of navigation (harbor, river mouth, etc.). Even numbers are on the right (starboard/red) side going in.

4. What color light, if any, is exhibited by a starboard-hand lateral buoy at night?

• A.Green
• B.Red✓
• C.White
• D.Yellow

Why: Starboard-hand (red/even) lateral aids show RED lights when lighted. Port-hand (green/odd) aids show GREEN lights.

5. A lighted lateral buoy shows a light rhythm of Fl(2) 6s. What does this mean?

• A.Two flashes followed by darkness, total cycle 6 seconds✓
• B.One flash every 6 seconds
• C.Six flashes then a long eclipse
• D.Alternating red and green every 6 seconds

Why: Fl(2) 6s means a group-flashing light with 2 flashes per group, the complete cycle lasting 6 seconds. The group flash and its following eclipse together equal 6 seconds.