The Offshore Voyaging Reference Site

Cool Supplemental Anchor Light

Some years ago Phyllis and I found out the hard way, when another yacht hit us, that sometimes boaters don’t look up and see anchor lights at the top of masts.

After that accident, we fitted a supplemental all-around white light on top of the radar on our McCurdy and Rhodes 56, as is allowed under COLREGS. Definitely the best solution.

I was just thinking about doing the same on our new-to-us J/109 when I remembered that our new B&G radar can display a blue light.

I have to confess that when I first saw that in the installation manual I thought “well, that’s the silliest feature I have ever seen on marine electronics, and that’s saying something”.

But now I have tried it, I take it back. And having the radar on standby with the light on medium intensity only uses 0.2 A at 12 volts.

And since it’s blue, a colour that is not used for any lights prescribed by the COLREGS, I’m pretty sure it’s perfectly legal under Rule 30.

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Kit Laughlin

Nice one, John. And I am sure that is legal under Rule 30 (and if not, someone else here will tell us for sure!). Very good idea.

Karl Lang

Hi John
I wonder whether it would be permissible to display a mast-top flash light at anchor – or strobe light as used on aircraft.
This would make for great visibility of the anchored yacht, even to a complacent oncoming boater.
Reading Colregs, part 30, it just specifies light color and range.
What is your take on this, please?
Best, Karl


The regs are read literally.
“ where it can best be seen: an all-round white light”.

So blue light would be a deviation. If you have a white light and a blue light that too would be ok, as the regulation specifies you may have your decks lighted while at anchor. If your craft is more than 100m in length
“ shall, also use the available working or equivalent lights to illuminate her decks.”

A flashing light alone is not adequate. It fails the all around element of the regulation as an anchor light.

Now if you have a mast and are anchored in or near a Seaplane landing area a red flashing light on your mast head may help. Not sure but there may be an aviation rule about that.

Terence Thatcher

John: I thought you only trusted Furuno radar? I need to replace my current unit. Can I trust the B&G, which cheaper than any good Furuno? Love to have your advice?

Terence Thatcher

Thanks. Sounds like I should go with Furuno. I use EBM (EBL on my machine) and VRM all the time in shipping channels. i.e. Juan de Fuca Strait.

Roland Stockham

This one bugs me, A LOT. No, flashing lights are not allowed. Under col reg’s. A white flashing strobe means you are a N Cardinal, Yellow flashing light means you are a hovercraft and a blue one police! Also the traditional (and best location) for the anchor light is in the fore-triangle. Can be either a battery one or a plug in hoisted on a halyard. The masthead is the worst place as it is almost guaranteed to get lost against the shore lights from anywhere other than a large ships bridge. In these days of super efficient and bright LED’s a battery powered one could be ideal but also if you have an LED flood for the deck that could be ideal and a great security measure to boot!

P D Squire

Speaking of Colregs and anchoring, do you think the Colregs require a person on watch at all times even while at anchor?

Robert Ellett

An anchor light at the top of a mast is like another star in the night sky! I prefer to shine a bike helmet LED light from the deck, in front of the dodger, up towards the mast. This lights up almost the entire mast and spreaders. It is certainly visible from a distance and defines the boat as a sailing vessel. In addition, i often hang a waterproof blue 15 foot led strip wrapped around a 12 inch long PVC pipe segment, from the aft arch. The boat is then distinctly identifiable for miles, and easy to find at night in a crowded marina. Any laws broken?

Dick Stevenson

Hi Robert,
My take is that if you have your anchor light at the top of the mast on, you can light yourself up in most any way you wish excepting any lights which might be taken for distress or navigation.
I largely just use and masthead anchor light and for decades have had a good quality reflecting tape on my anchor platform and on my vane steering gear, port and starboard. I also have this reflecting tape up high on both sides of the mast.
It is impressive how this tape takes most any ambient light and pops out at you.
Some boats I see are using flashing lights of various colors which I find annoying and distracting in a nice peaceful anchorage.
I am usually not in crowded anchorages, but think some deck level light is warranted when I do. I like your LED wrapped pvc tube idea for its distinctiveness and for its likely ease on the eyes if I need to come on deck and want to save my night vision
My best, Dick Stevenson, s/v Alchemy