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Navigation Lights on our Explorer Yacht

Updated: Apr 20

Happy New Year to everyone, a year of change for us is coming!

After we sketched out the basics of our navigation mast and located all the major components, the time came to assemble the Navigation Light specification and place them appropriately. We are being certified under UK Marine Coastguard Agency as Category (0), the UK interpretation of COLREGs 1972 is MSN 1781 and its amendments. Not the most scintillating read, a bit confusing at times, but also a set of rules that every navigator needs to know and understand. MSN 1781 covers rules of the road, navigation lights, horns, and an ethos that accidents will be your problem, so avoid them. A copy of MSN 1781 can be found below.

msn 1781
Download PDF • 512KB

Armed with this, here is how the navigation light requirements flow.

Firstly, to define ourselves by what we are not. Not a fishing boat or trawler, pilot boat or skiff, pusher or a puller tug or a dredger. We are not "constrained by draft" or "sweeping mines". Vanguard is a motorboat, and the length category is 20<>50m.

That makes life relatively clear. So we know this category will have 2NM or 5NM range lights, marine-approved, watertight, consistent illumination LEDs.

The case for double lights in the event of failure probably passed on vessels out of Class with the introduction of LED at circa 10,000 hours between failure. Besides this, we have an alarm if it happens en passage - so single bulb units and a spare LED or two.

Vanguard is fitted with a Praxis Navigation Light controller and has some preset conditions covering the lights we need.

Those are:

  • Steaming

  • At Anchor

  • Not Under Command (NUC)

  • Naval Yachts suggested we also add RAM, Restricted Maneuvering; not sure why, diving maybe but I was in a good mood, so I agreed.

  • Individual Operation

Shown - example of a Navigation Light Controller fromPraxis Automation.

So let's look at the requirements of each in succession:


  • Mast Head Light, 5NM, white, 225 degrees forward

  • Stern light, 2NM, white, 135 degrees aft

  • Portlight, 2NM, Red, 112.5 degrees port forward

  • Starboard light, 2NM, Green, 112.5 degrees starboard forward

At Anchor