Alignment of Navigation Lights?

[troppo]

I am planning on replacing the navigation lights on my new (old) sailing boat. The old port and starboard lights are on the hull in the bow. What I am wondering is if I just buy sidelights and stick them on, how do I get the proper alignment?

What I mean by alignment is the regulations which say the lights cover from straight ahead to 22.5 degrees abaft beam. How do I get those correct angles? If I change where I stick the lights then the angles would also change so I guess there must be some way of adjusting the alignment.

What is the best way to align them to match the regulations?

[Target9000]

Place them where you think you'll be mounting them and then turn them on and measure the angles. See if they're correct. Most manufacturers provide lights that are designed to mount with their "back" perpendicular with the center line of the hull making it pretty simple to install.

[troppo]

Looking at the old navigation lights in the hull below the gunwale, it appears that they may not have complied with the regulations. Looking at the front of the boat, it looks like you could be a fair way to the side and still see both lights. There are no screens inside these lights to give the correct angles, they are just plastic bubbles.

Also, I came across some discussion about not having the lights below the gunwwale. Is that actually a regulation that you can't have them there?

If I put the new ones where the old ones are I would probably need to 'glass in a base with the proper orientation.

[Ex-Calif]

Originally Posted by troppo

Looking at the old navigation lights in the hull below the gunwale, it appears that they may not have complied with the regulations. Looking at the front of the boat, it looks like you could be a fair way to the side and still see both lights. There are no screens inside these lights to give the correct angles, they are just plastic bubbles.

Also, I came across some discussion about not having the lights below the gunwwale. Is that actually a regulation that you can't have them there?

If I put the new ones where the old ones are I would probably need to 'glass in a base with the proper orientation.

That definitely looks sketchy.

If it were me I would remove the old ones and glass them in and look to mount a port/starboard combo unit on the pulpit. Might hae to manufacture a bracket but what you have looks off.

[Hud3]

Those look like they'd be practically invisible in a seaway. I'm with Dan--put a proper AquaSignal unit up on your pulpit.

[Tony B]

I am sure that if you replaced your existing lights you would be just fine.
Keep in mind that when you are sailing, your bow will swing somewhat side to side with the waves and if you are coming dead on to someone, you dont want to have one of your nav lights winking on and off due to just a small angle. If yours dont have screens inside to give you the correct angles it is probably becase of the placement on the hull. You will not or should not see your nav lights from the rear.
If you don't want to do that for some reason, buy the combo lights as suggested by the others. Nav lights should have built in reflectors to give you the correct angle.
I think you might be over thinking this

[barnakiel]

If feasible, use singe port/stbd light on the fore part of the metal frame visible in the image. You will need one fixture only and have the lights way higher above the water.

b.

[Wotname]

Ahh... another one of my pet hates, PT & STBD lights just jammed on without any thought of correct alignment. See it all the time, usually by the manufacturer .

I vote with those who say put them higher and align them to the centre line of the boat; you will need a custom bracket or wedges etc.

[jeremiason]

No one from the IMO or any other marine regulatory organization is going to come out to your boat and measure the angle of degrees on your navigation lights.

The official regulations require the lights to be:

Red an arc of 112.5 degrees
Green an arc f 112.5 degrees
White an are of 135 degrees

If you add that up, it makes 360 degree circle of light around your boat. That is what you are trying to achieve.

If you sit on an active fairway at night you wll notice that many vessels have partially obstructed navigation lights, mostly from add on things, like biminis, davits or cargo. Not to mention, just plain inappropriate lighting...

We sailboaters are the worse offenders of not having correct lighting. My hypothysis is that power boats have one switch for running lights and one switch for anchor lights.

On the other hand our sailboats have multiple choices (Tri-Color, Anchor and Running), which usually leads to someone turning on the wrong switch or thinking that turning on the tri color with his running lights will make them easier to see. The problem is that from a distance another vessel now sees two sailboats.

The best way to install the lights is to have them as high on the vessel as possible and mounted in a way they are not obstructed.

I notice in the picture, you vessel has lights mounted on the bow. I had an old Catlalina 27 with the same configuration. My suggestion would be move the new lights to the bow rail, which will provide better visibilty, by raising them a couple feet higher off the water.

With the new LED Lights, power is no longer a consideration, so using separate fixtures for red and green nav lights is no problem and again provides more visiblity.

Good luck!

[David M]

I agree with getting a combined port/starboard and mounting it on the pulpit. Align it at the dock by getting maybe 200 feet away directly in front of your bow and see if the bow and stern light are of equal brightness and then walk to each side a few degrees of arc to see if the other light on the opposite side fades equally....that is good enough.

Also consider a brighter light. 1 mile sidelights are quite often not bright enough. You are allowed to have brighter lights than what your length requires. (maybe consider 2 mile sides) If you do you will need to step up your white lights brightness as well. It is easier to do this on boats that run on battery power only, now that LED's are available that draw much less power.

[Hud3]

Originally Posted by jeremiason

No one from the IMO or any other marine regulatory organization is going to come out to your boat and measure the angle of degrees on your navigation lights...

You're probably right, Tom, but believe it or not the Coast Guard stopped me in the Manatee River near Bradenton, Florida, and told me they thought my bow lights were visible too far aft. I explained that they were factory installed AquaSignal lights which are pretty much standard equipment on tens of thousands of boats. That seemed to satisfy them.

[Cheechako]

Originally Posted by Hud3

Those look like they'd be practically invisible in a seaway. I'm with Dan--put a proper AquaSignal unit up on your pulpit.

Yep... what he said. Also, There is an aqua signal light that is port and starboard in one light. It could mount on the front of the pulpit. using a proper thru deck gland for the wire. many boats run the wire through the pulpit, but that's a lot of work!
Maybe using individual lights mounted at the first pulpit cross bar would be less obtrusive wiring for you.

If you hate glassing....it almost looks like you could install two drains for the anchor locker where those lights are!

[jeremiason]

Originally Posted by Hud3

You're probably right, Tom, but believe it or not the Coast Guard stopped me in the Manatee River near Bradenton, Florida, and told me they thought my bow lights were visible too far aft. I explained that they were factory installed AquaSignal lights which are pretty much standard equipment on tens of thousands of boats. That seemed to satisfy them.

I stand corrected... Thanks

[senormechanico]

+1 for the LED nav lights!

Just yesterday I installed Dr. LED 2 mile bicolor and stern lights.
They draw 0.180 amps instead of 3 amps, and they're every bit as bright if not brighter.
I had a narrow yellow sector (+ or - 3 degrees) straight ahead with the bicolor, so I fashioned a vertical divider from a thin sheet of metal and installed it in the lens.
Now the red/green intersection is perfect.

Nav lighting is every bit as important as good headlights on a car.

[hellosailor]

troppo, if you do a lot of night sailing, LED lights can quickly pay for themselves because of the lower power consumption. I'd agre with the folks who suggest a combined bow pulpit light, quicker and simpler than anything else and equally effective. Or a masthead unit if you prefer.

But the existing lights in the hull? If they don't leak, leave them in place instead of worrying about fixing two holes in the hull. If they work, just pop in new bulbs and leave them as spares "just in case". Removing them is a nice idea, but then you've got to plug the holes, or repaint the hull, and I'd rather spend the time sailing.<G>