Navigation Lights on Mast for small tug

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Aug 21, 2023
Hello, putting a 12' mast (2" aluminum) forward of pilot house on a Crosby 26', along the lines of some vintage tugs. Curious if OK to put stern and tow light on the mast in addition to masthead(s), all round and combo running light? Each will meet the required visibility requirements, just not sure stern and tow can be that close in proximity to forward facing lights?
I haven’t checked the regs lately, but for your length, I thought the all around light on the masthead qualifies as the stern light.
Yeah, I was thinking same, but it's not clear. unless your a sailboat, at least that's my uneducated guess. I'm a visual learner, hey never have a diagram of small tug towing on the light pages. My concern is the language in the regs, "nearly as practicable at the stern".

“Sternlight” means a white light placed as nearly as practicable at the stern showing an unbroken light over an arc of the horizon of 135 degrees and so fixed as to show the light 67.5 degrees from right aft on each side of the vessel.
(d) “Towing light” means a yellow light having the same characteristics as the “sternlight” defined in paragraph (c) of this Rule.
I’m thinking the all around white counts as the steaming light and stern light. Then the tow light would mount lower on the mast on the back side so only visible from the stern.
If you’re not really a tug, and doing it for the look, you may have some leeway.
As far as I know, having it all on the mast is legal. If you're worried about separation, just put the stern and towing lights a bit lower than the masthead light.
Wouldn’t there be a stacked set of white to signify towing? Where’s our resident expert?
Thank you both! She's a tug, but she'll see only light work at 26'. We'll go with mast and good separation. The masthead(s) lights in combo w/ tow, running & stern lights signify towing.
On our assistance towboats, we had a short mast where the masthead and yellow towing light were located...but the sidelights and stern lights were mounted on the top of the pilothouse roof at the outer edges. Not sure that matters for your planned configuration of tug lights. The masthead and sidelights should only be seen at once and the tow/stern light at a separate time depending on your location.


RULE 24 - Inland
Towing and Pushing
(a) A power-driven vessel when towing astern shall exhibit:
(i) instead of the light prescribed either in Rule 23(a)(i) or 23(a)(ii), two
masthead lights in a vertical line. When the length of the tow,
measuring from the stern of the towing vessel to the after end of the
tow exceeds 200 meters, three such lights in a vertical line;
(ii) sidelights;
(iii) a sternlight;
(iv) a towing light in a vertical line above the sternlight; and (v) when
the length of the tow exceeds 200 meters, a diamond shape where it
can best be seen.


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Here is a small tug with most lights on the mast....


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The illustration psneeld posted is what I’m familiar with. But I think with the smaller tug, keeping everything on the mast is fine. If the yellow stern light needs to be above the white stern light it would eliminate using an all around white for steaming/stern combo.
I do think I’d separate the fwd facing from the reverse facing lights. Different elevations may help to keep the colors from blending at certain angles, and make it easier to tell where the stern is.
Just keep in mind the mast head light (Forward facing white) must be at least one meter above the red-green side lights. That and placing the yellow towing light one meter above the stern light could make a really tall mast for such a small boat. And these extra lights may only be lit when actually towing something. Towing a dinghy would count. These "activity lights" are only required on boats that do the activity for a living, no one expects them to be on a pleasure boat. If you're just putting the extra lights on for show and don't intend to use them, I suppose you could cheat on the spacing and make them more in scale to the size of the boat.
Pretty sure this vessel meets the exemption requirement and just shall "attempt" to comply. Many smaller vessels don't meet the "one meter" rule....our assistance tow fleet didn't.



There are too many to post but the essence of it is vessels 12 meters and less are pretty much exempt from the hard rules but shall try to comply the best they can.
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Thank you both! She's a tug, but she'll see only light work at 26'. We'll go with mast and good separation. The masthead(s) lights in combo w/ tow, running & stern lights signify towing.

When do we get pictures of this tug?!
TBI/Crosby 26 Lighting

Hi Willie,
This is what we did on our 1973 TBI (later Crosby) hull #7. But for the side lights (which were mounted on the side boards above the deck house), all lights were on the mast.
Greg Lee
Roche Harbor, WA


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