3D Mark Viewer
3DIALA lateral marks (Region A & B)
Lateral marks indicate the port and starboard sides of a channel relative to the conventional direction of buoyage, with colours reversed between IALA Region A and Region B.
Detailed Explanation
Lateral marks define the edges of a navigable channel:
Region A (Europe, Africa, Asia except Japan/Korea/Philippines):
- Port: red, can/cylinder topmark, red light (any rhythm)
- Starboard: green, conical topmark, green light (any rhythm)
Region B (Americas, Japan, Korea, Philippines):
- Port: green, can/cylinder topmark, green light
- Starboard: red, conical topmark, red light
The conventional direction of buoyage (shown on charts) determines which side is 'port' and 'starboard'. Generally: entering from seaward, going upstream, or clockwise around a landmass.
Preferred channel marks (modified lateral): indicate the preferred channel at a bifurcation. Use horizontal bands of both colours; topmark and colour of the band at the TOP indicates the preferred channel side.
Key Points
- Region A: red = port, green = starboard (entering from sea)
- Region B: reversed — green = port, red = starboard
- Check conventional direction of buoyage on chart first
- Shape: can/cylinder = port, cone = starboard
Examples
- Entering a European port (IALA Region A) you see a red can buoy with Fl.R to port and a green conical buoy with Fl.G to starboard. You keep the red mark to port and the green to starboard as you proceed inbound.
- Transiting the US ICW (IALA Region B) you encounter a red nun buoy to starboard. The mnemonic 'red right returning' applies — Region B reverses the color/side convention relative to Region A.
- At a channel junction you see a red-and-green horizontally banded buoy with the preferred channel to starboard. The top color band indicates the preferred channel direction under IALA lateral rules.
Common Mistakes
- Applying Region A color conventions (red to port) when navigating in a Region B area, or vice versa.
- Forgetting to check the direction of buoyage on the chart before interpreting which side is port or starboard.
- Confusing a red can buoy with a red spherical safe-water topmark and treating them as the same type of mark.