Power Boats 12m to 20m Navigation Light Rules

The rules are pretty clear, see below, and There are no height requirements for the mast head light. On my 53 Hatteras MY the masthead light is on the forward slanted face of the FB housing, barely higher than the sidelights and well below the rest of the FB.

the only light which has to be at the top since it needs to be visible all around is the anchor light. That may have to be on a ratchet mount.

personally I don’t like sealed led fixtures as when they fail, you can’t replace the bulbs. I have standard perko fixtures and out LED bulbs which I can replace in 30 seconds. Yeah I know…. LED last forever. BS



(a) “Masthead light” means a white light placed over the fore and aft centerline of the vessel showing an unbroken light over an arc of the horizon of 225 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on either side of the vessel, except that on a vessel of less than 12 meters in length the masthead light shall be placed as nearly as practicable to the fore and aft centerline of the vessel.

(a) A power-driven vessel underway shall exhibit:
(i) a masthead light forward;
(ii) a second masthead light abaft of and higher than the forward one; except that a vessel of less than 50 meters in length shall not be obliged to exhibit such light but may do so;
(iii) sidelights; and
(iv) a sternlight.

I'm at my desk looking it up.
Let make sure I'm reading correctly;
You want to install your combination steaming (mast head) AND anchor light and worried about the vertical distance above your separate red-green lights?

So far, I found this in the annex;
3c The masthead light of a power-driven vessel of 12 metres but less than 20 metres in length shall be placed at a height above the gunwale of not less than 2.5 metres.

Anchor lights, Rule 30
(a). A vessel at anchor shall exhibit where it can best be seen:
(b). A vessel of less than 50 metres in length may exhibit an all-round white light where it can best be seen instead of the lights prescribed in paragraph (a) of this Rule.

Annex 1

(i). The masthead light or lights prescribed in Rule 23(a) shall be so placed as to be above and clear of all other lights and obstructions except as described in subparagraph (ii).


Still looking

Think I found something;


(g). The sidelights of a power-driven vessel shall be placed at a height above the hull not greater than three quarters of that of the forward masthead light. They shall not be so low as to be interfered with by deck lights.
(h). The sidelights, if in a combined lantern and carried on a power-driven vessel of less than 20 metres in length, shall be placed not less than 1 metre below the masthead light.

I read this; A combo red-green must be spaced 1 metre below.

Your red-greens are separate. No worries.

I've re-read that (g) line a few times now.
Government lingo can be fun.

not greater than three quarters of that of the forward masthead light

This could be a concern.

Example;
Your side lights are 7' over the gunnel.
Yep, near 3' spacing to the steaming light.
Interesting.

I think Ken answered your first question best.

Crazy, I never thought about this height stuff before.
Makes ya want to stay factory? Maybe there was an exception filed by Cabo.
But once you modify it, Any exceptions are gone.

Good thread. Think we all learned something today.

It s ridiculous. How do you define height above the hull anyway… from the deck?
many boats have the factory installed masthead light fairly close in height to the sidelights

I'm aweigh from my desk and can not copy/paste the line, but the annex did explain to measure from the main deck / gunnel below the steaming light.

Here it is;

Annex I - Positioning and Technical Details of Lights and

Shapes

1. Definition

. The term “height above the hull” means height above the uppermost continuous deck. This height shall be measured from the position vertically beneath the location of the light.