Peter,
I have a similar question to that of the original poster. My 32 ft boat was
modified by a previous owner. It has the following lights:

- Masthead Trilight - red/green/white
- Masthead 360 deg white light below tri-light
- Hull mounted conventional running lights red/green/stern white ( I added
these - the originals were not working)

I have read the regulations and find there are several variations. What I
have gathered is that a sailboat under power must display same lights as a
power boat.

In my case, under sail, I have two choices - either use the hull mounted
red/green/stern lights or use the masthead tri-light - both acceptable.

Under power, I do not have the normal steaming light. It seems from the
following quotation that I may be able to use the hull mounted lights plus
the masthead 360 deg light:

"If a power-driven vessel underway is less than 12 m long, it may display,
from sunset to sunrise, an all-round white light and sidelights instead of a
masthead light forward, sidelights, and a stern light. The all-round light
must be higher than the sidelights."

I would sort of have this, but from the stern there would be two white
lights showing, one low and one high.

I read the following in the international colregs:

"the masthead light or all-round white light on a power-driven vessel of
less than 12 meters in length may be displaced from the fore and aft
centerline of the vessel if centerline fitting is not practicable, provided
the sidelights are combined in one lantern which shall be carried on the
fore and aft centerline of the vessel or located as nearly as practicable in
the same fore and aft line as the masthead light or all-round white light."

This would tend to say that the combined masthead trilight plus all round
light might also be acceptable.

I could add the conventional mast mounted steaming light, but this means
adding wiring and switches. Question is, do I need to do it!

Graham






"Peter Bennett" wrote

The light you are asking about is the "steaming" (not streaming) or
masthead light. It has an arc of visibility from dead ahead to two
points (22.5 degrees) abaft the beam on either side - it covers the
same arc as the red and green sidelights.


The Collision Regulations will describe the required positions of all
navigation lights.

According to the Canadian version of the Coll Regs, on a vessel under
12 metres, the masthead light must be at least 1 metre above the
sidelights.

--
Peter Bennett, VE7CEI