New bow nav lights...alignment?

[vizwhiz]

Picked up some inexpensive side nav lights, vertical surface mount, teardrop shape, in black, to mount on the bow so I can get rid of the one combo light that is up on the pulpit deck (mine is not on the railing, but down on the deck in the way). They were inexpensive, they're bright, and look pretty good.

As I was fitting them to the black striped area under the rub rail, i noticed that the slope of the hull at the bow, the slight v-shape, makes them angle down. It seems that this would seriously impact the ability to see them from the side at a distance, so i was thinking i should make a little wedge for under them so they will be more vertical. Then looking at them from the front, i also realized that they weren't pointing straight forward because of the pointy shape of the bow. I adjusted the wedge shape to help straighten them out.

Am I being oversensitive to how they're mounted, or is this effort on track? I'm thinking these are pretty important lights, both from the regulatory perspective and the situational-safety perspective. Do they even have to be on the bow, or just forward-facing? (Thinking of how a tri-color light is very close together.)

Has anyone else done this with their bow nav lights? Ideas?

[Russ]

Alignment is important. Location, not as much.

Rule 21 - Definitions

"Sidelights" means a green light on the starboard side and a red light on the port side each showing an unbroken light over an arc of the horizon of 112.5 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on its respective side. In a vessel of less than 20 meters in length the sidelights may be combined in one lantern carried on the fore and aft centerline of the vessel, except that on a vessel of less than 12 meters in length the sidelights when combined in one lantern shall be placed as nearly as practicable to the fore and aft centerline of the vessel.

[NiceAft]

It seems like a lot of effort to correct something which does not need correction.

Raay

[vizwhiz]

Thanks Russ...that helps with the legalities...

Ray, not sure what you're suggesting doesn't need correction...
The light being located up on the foredeck has been kicked off before, and was dangling loose (held by the wire) when I bought the boat. I have also kicked it myself, or stepped on it, many times while climbing onto the boat via the trailer step. Also, I have been enviously eyeing the guys with anchor rollers, so I'm trying to make preparations should I go that route. In any case, that light is in a bad spot. So that would be why the location needs correcting, if that was what you were referring to.

As for the new nav lights, they essentially have a rectangular cut-out window that the light shines out of...kinda looks like the racoon stripe on an X/M. I was trying to mount these near the front of the boat, if possible, and with the boat sloping in V-shape up there, that window is angled downward toward the water instead of straight out sideways. Also, because the boat tapers to a point, the two lights angle inward toward each other (kinda cross-eyed like), so they won't be visible as far back as they need to, and may give cross-over lighting to the opposite side, both no-no's. So...that's why the alignment needs to be corrected, if that was what you were referring to.

I was trying to figure out a way to make them point straight forward and be vertical instead of angled down...oooorrrrr...put them in a different place on the boat where that might not be such a problem.

[Tomfoolery]

Those lights are almost certainly designed for mounting on a vertical surface, parallel to the bow/stern centerline, so if mounting at the bow, you should make wedges to align them. There is specific performance criteria for side lights, including the rate at which they 'disapppear' past the 112.5 degrees angle (22.5 degrees abaft the beam), as well as how much light they emit above and below 20 degrees of boat heel (if memory serves - it's in the COLREGS), and I believe lights are also rated for powerboats and sailboats, which are different due to heeling.

There is also no requirement that they be at the bow. They're technically called 'side lights', and small boats (under 12m, or maybe it's 20m, I think) can have a single bi-color at the bow, but larger boats have them usually above the pilot house, which is a long way from the bow, and small boats like yours can do that also if you choose. You wouldn't need much of a wedge if mounted further back.

[Tomfoolery]

Here's a post I put up a while back on the subject, with some crappy graphics:

I also have some concern with the angle of the lights with them mounted far forward, the bow angle would mean the radius is shining further forward. So less visible from a vessel abeam
Dunn’s install has them at the beam so the angles would be right, but I don’t like that position myself.

I'd be concerned, too. Depending on the angle of the hull at the bow, you can get a pretty wide window where no lights can be side on either side, and a pretty big window off the bow where both can be seen.

Proper installation has no point unlit . . .



but angled toward each other, you can have a very wide area that's unlit under sail, or showing white (masthead) only even when looking straight at the beam or even a little forward of it . . .



by the better part of half a mile wide dead zone when one mile away, in the pic above (just an eyeball estimate of the bow angle). Doesn't sound too bad unless it's a go-fast boat that's going fast in the dark, or a freighter, or not-so-good weather when it's hard enough as it is without an invisible boat in front of you. Just sayin'.

And the thread it came from:

http://www.macgregorsailors.com/forum/v ... =9&t=21711

[Catigale]

Viz ..if you are inland lake sailing in the daytime, no worries.

Nighttime on coastal waters? Get it right....