Col Regs and IALA

IALA International Association Of Lighthouse Authorities

The IALA is primarily known for its buoyage systems that are used in the pilotage of vessels at sea.

Regions: Two regions exist around the world. IALA region A and IALA region B. Region B covers the whole of the Americas, Japan, South Korea and the Philippines, while the rest of the world belongs to region A.

IALA buoyage system A: When entering a port or going upstream, green buoys (cones) will be on your starboard side, red buoys (cans) will be on your port side; when leaving port or heading downstream, the green will be on your port and the red on your starboard.

IALA buoyage system B: If you are in a country that uses the B system, when entering port or going upstream, red will be on starboard and green on port side, when leaving port or heading downstream, the green will be on your starboard and the red on your port.

Navigation Lights

You can tell which way a vessel is heading by their navigation lights. If you see both green and red lights of another vessel, it is heading towards you. Of course, the red light is their port light and green their starboard light, but ships can have many different lights. Their navigation lights can become lost within other lights i.e. cabin lights or deck lights.

Keep a book on board of the complete International Collision Regulations so you can identify their light signals, such as:

  • ‘Not Under Command’ (two all round red lights, one above the other – vertically).
  • ‘Restricted In Ability to Manoeuvre’ (three all round lights, red, white, red, one above the other – vertically).

The priority of the ‘give way vessel’ and the ‘stand on vessel’ changes for different vessels and different circumstances. You need to know the rules and how to react before a close quarters situation develops.

When coastal cruising, be aware that ship lights between you and the coast can be lost within the shore lights. Maintain extra vigilance, particularly in harbours.

Large ships can take a long time to stop and/or alter course. Their momentum carries them a long way.

Image 89 Col Regs
Image 89 Col Regs

Collision Regulations: Do you know what these signals mean?

They tell you what the boat is doing and which side is safe to pass.


What are the night-time lights for this vessel?

Answer: This vessel is Restricted in Ability to Manoeuvre (RAM) as it is dredging. It is safe to pass on the side of the two diamonds.


The black ball, black diamond, black ball in a vertical line tell us that the vessel is RAM.

The two black balls on one side tell us NOT to pass this side, this is where the area of danger exists.

The two black diamonds tell us that this is the side we must pass, i.e. it is the safe side to pass.

At night-time, or in restricted visibility, the RAM signal is a vertical line of lights: red-white-red.

The side to pass (black diamonds during the day) will be two vertical green lights.

The side of danger (not to pass), indicated by two black balls during the day, will be red vertical lights at night (or in restricted visibility).

Sunset To Sunrise: We’ve known some cruisers to turn their navigation lights off at night to conserve power, and some do not turn them on at all. I think this is a very bad idea and breaks all the rules of good seamanship. Fit LEDs. Aside from an emergency, if you do not have enough power to run lights then you should not be out there at night. The oceans may seem large, but on most trips we have had to change course for other vessels. What if they can’t see you? If you’ve fallen asleep? If another boat is ‘running blind’ also?. . . Is it worth it? Invest in LED lights, particularly for the masthead lights.