During the hours of darkness we rely on lights to tell when other boats are nearby, whether they are moving and in what direction they’re travelling in.  The international regulations that describe what lights should be shown are part of the COLREGS (“International Regulations For Preventing Collisions At Sea”, see here).  Despite the intimidating name, these are intended to be read by normal people and are written in plain language.  They cover lots of different situations, so if you have a smaller sailing boat it’s useful to focus down on just the parts which apply to your kind of boat.

Firstly, let’s deal with one common misunderstanding before we dive in.  A “masthead light” does not mean “any light at the top of your yacht’s mast” like you might expect.  It’s better to think of it as meaning a “white light on a pole”.  An oil tanker doesn’t have sail nor a mast but it (as a powered vessel over 50m) is obligated by COLREGS to have two masthead lights – one near the bow and another slightly higher one further back.  Masthead lights almost always live on the fore/aft centreline of the boat, and they’re only visible from ahead of the vessel but not from behind (more precisely, from 22.5 degrees abaft the beam on both sides).  On a sailboat, you could have your “masthead light” on your mast, but it doesn’t technically have to be there.

A yacht can either be:

  1. A “sailing vessel underway” if you’re moving with your engine off
  2. A “power-driven vessel underway” if you’re moving with your engine running
  3. An “anchored vessel” if you’re at anchor, or even..
  4. A “vessel aground” or “vessel not under command” if perhaps your rudder has fallen off.   

The COLREGs is structured with separate sections for each situation, explaining the differing light requirements for small and large vessels.  In this article, we’ll approach it in a slightly different order – listing firstly the requirements for a small boat, then all the requirements for a larger boat.

Sailboat less than 7 meters

  • You are allowed to sail with just a torch to be “exhibited” in sufficient time to avoid a collision.  However, if “practicable” then you should sail showing the lights required for slightly larger boats below.
  • If you’re anchored away from narrow channels, anchorages and generally other boats you technically don’t need to show any lights at anchor – but otherwise  you must show an all-round white light (“anchor light”) visibly in the fore part of the boat.
  • If you’re moving under power below 7kts, an all-round white light is sufficient.  But you’re encouraged to also show sidelights as per a larger boat.

Sailboat less than 12 meters

  • Under sail, you need either:
    • A “tricolor” light at the top of your mast.
    • Or, a white sternlight (showing rearwards) and separate red and green sidelights.
    • Or, a white sternlight and a combined unit showing red/green to sides mounted anywhere on the boat’s centerline.
  • At anchor, you need an all-round white light “where it can be best seen”.
  • Under power, the “tricolor” isn’t an option – you need need sidelights AND either:
    • An all-round white light (since you are less than 12m)
    • Or, a masthead light forward (white, front-facing) and a sternlight (white, rear-facing).

So for a small boat, an all-round-white light plus bicolour covers power and anchoring, and either a mast-top tricolor or additional sternlight covers

(photo credit: Flickr)