Side Nav Lights

[firstbase]

On to my next anal subject. Replacing my side of cabin name boards that hold my nav lights and noticed something. My old Perko lights are in a 90 degree casing. They are supposed to be seen from dead ahead to 22.5 degrees abaft beam. OK, how does that work? The PO of my boat had the name boards set up so they angled a bit towards the stern. Meaning the spacer at the forward end of the board was thicker than the one towards the stern. But....if that is done doesn't it mean that there would be a blank space in-between the lights from dead ahead? How do set up 90 degree lights so they are seen appropriately? I do notice that the lens is not 90 degrees but is curved a bit at each end where it falls into the casing. Does that take care of the issue? Just set them up for and aft with the center line of the boat and the lens does the work?

 

[psneeld]

Usually the filament of the buld is forward just enough of the 90 degree housing to give tou the 22.5 degrees abaft the beam.

As far as aligning with the centerline with ehr boat, generally they should be, usung spacers to do so.

The name boards are a secondary function and only really a recreational thing to be included with "light screens" for the nav lights to ensure proper sectors.

 

[AusCan]

Have a close look at the bulb placement.
The casing may look like it cut off at 90 degrees, but usually the bulb is mounted forward of the edge of the casing, so it will provide light at the required angle aft when mounted flat.
To be sure, walk around the boat at the dock with a protractor at night.

Mine are slightly out of alignment which I need to correct. There is a slight overlap from ahead due to being mounted on the curved bow rail. It requires a spacer as your old boat had. It's on my project list.

 

[firstbase]

Thanks guys. Looking at them with all that in mind I can see how they can cover the area but only if placed correctly. Also see that it might take a little trial and error on the spacers and adjustment in how far outboard the light sits on the name board base. I have a "back board" that blocks the light from the rear. Have to make sure the lens is far enough out so that it shines around that back board.


Thanks for the comments and help.

 

[TomandJeri]

Sidelights alone should cover the required arc, with the required intensity within the arc and the required cutoff within (I think) 1-3 deg. arc at each end, so yours are more for aesthetics than function, as long as the lights are USCG approved sidelights. You can mount them a little further forward of the aft return, as it's not actually required to screen the light from 22.5 deg. abaft the beam. But like you, I'd probably measure off 22.5 deg abaft the beam, and see if the center of the vertical filament bulb is just visible (with a protractor) where the screen cuts it off, just to make sure, and move the light forward if it cuts it off prematurely.


72 COLREGS, Annex I

5. Screens for sidelights
The sidelights of vessels of 20 meters or more in length shall be fitted with
inboard screens painted matt black, and meeting the requirements of
Section 9 of this Annex. On vessels of less than 20 meters in length the
sidelights, if necessary to meet the requirements of Section 9 of this Annex,
shall be fitted with inboard matt black screens. With a combined lantern,
using a single vertical filament and a very narrow division between the green
and red sections, external screens need not be fitted.

 

[psneeld]

It is annoying that the colored lenses on the brighter nav lights stick out just enough, it is possible to see them from behind the boat.

Till I put screens on all our assistance tow boats, you could be behind them a couple hundred yards and still see the colored lenses.....much like the intensity of some cheapo side lights on small vessels.

Must have driven a lot of boats crazy for many years running around bends on the IICW and seeing nav lights that you think should be coming at you, but then realizing they are on the wrong sides.

Wonder how many other boats do the same thing.

 

[High Wire]

It is annoying that the colored lenses on the brighter nav lights stick out just enough, it is possible to see them from behind the boat.

Till I put screens on all our assistance tow boats, you could be behind them a couple hundred yards and still see the colored lenses.....much like the intensity of some cheapo side lights on small vessels.

Must have driven a lot of boats crazy for many years running around bends on the IICW and seeing nav lights that you think should be coming at you, but then realizing they are on the wrong sides.

Wonder how many other boats do the same thing.

You would be lucky if one in twenty even noticed. Thats probably high.

 

[psneeld]

​

You would be lucky if one in twenty even noticed. Thats probably high.

Rare on a summer night that 1 in 20 are showing correct lights anyhow...

 

[Comodave]

We were patrolling for the fireworks this year, about 60% of the boats that were out were improperly lit. Some didn’t even have a light aboard...

 

[firstbase]

Thanks to all. Another boat item that I never gave much thought to in the past. Can't say that I ever changed or messed with any in all my years. Looking at these (Perko) nav lights I do see the bulb placement and I see that despite the 90 degree casing the lens is a little proud of the casing which allows light to angle back. I do have returns behind them but can adjust them outward with spacers as needed. Going to install on the centerline, take some measurements/angles and go from there.

 

[bglad]

Boat structure is rarely done with a square or straight edge. I imagine your flybridge tapers inward a bit going forward so the forward block would be larger to hold the light fixture perpendicular to the vessel centerline.

 

[firstbase]

This whole thing was due to my changing of the name of the boat which was on the old name boards, same nav lights. I reused the old spacers on the new boards. I assumed they were at least close to accurate. You are right, the rear spacers are thinner than the ones forward.

 

[markpierce]

If you are showing a white running light without red or green sidelights showing, I'm to presume you are heading away from me. If only your white masthead light is showing, I'd be disappointed if headed straight for me. (Memo to self: check radar to observe changing distances.)

 

[markpierce]

This whole thing was due to my changing of the name of the boat which was on the old name boards, same nav lights. I reused the old spacers on the new boards. I assumed they were at least close to accurate. You are right, the rear spacers are thinner than the ones forward.

I'm (sort of) trusting that both green and red sidelight are visible from the forward position.

 

[FF]

This thread might be incentive for a cruiser anchored out on a fine night to take a 360 in the dink and observe your boats lights.

Are they correct , or sending false information to other vessels?

Our only "non standard" light is a far larger anchor light.

With LED it is easy to get to 5 miles viz , even tho the requirements are much lower.

Having perhaps the brightest light in the harbor makes rowing back from an evening ashore a snap.

 

[firstbase]

I'm (sort of) trusting that both green and red sidelight are visible from the forward position.

Yes but from how far out? That's going to be the first check I do after re-install. Luckily I have open water in front of my slip and dock stern in. At some point the cabin has to block them from head on but I think it is a fairly close distance. Coming from a sailing background on boats larger and smaller that all had combo lights on the bow, never thought I would have to give this much attention to them.

 

[firstbase]

This thread might be incentive for a cruiser anchored out on a fine night to take a 360 in the dink and observe your boats lights.

Are they correct , or sending false information to other vessels?

Our only "non standard" light is a far larger anchor light.

With LED it is easy to get to 5 miles viz , even tho the requirements are much lower.

Having perhaps the brightest light in the harbor makes rowing back from an evening ashore a snap.

Yep, plan on having the wife on board with some shims as well so we can get it done in one shot. Also need to make sure that the base of the light is angled down just a touch for water run off. Light isn't resting on the board, it is held above it 1/2" or so by the attachment bracket behind but still need some angle for run off.

 

[TomandJeri]

Yes but from how far out?

From the COLREGS, Annex I (technical details):

"In the forward direction, sidelights as fitted on the vessel shall show the minimum required intensities. The intensities shall decrease to reach practical cut-off between 1 degree and 3 degrees outside the prescribed sectors."

With a 12 ft separation, at 1 deg. cutoff, the minimum distance from the lights is about 344 ft to the point where they're both still visible. At 3 deg. cutoff, the minimum distance where they're both still visible (on the centerline, of course) is about 115 ft. Either side of that theoretical point and you lose one of them, but further away the sector where you can still see both grows.

 

[rgano]

If you look very closely at the photo of my boat, you will see one of those useless "combined" sidelight fixtures on the top side of my anchor pulpit. Checking it out by walking around in the backyard after I got it home into the lift, I found that both colors were quite visible at over thirty degrees off the center-line. Many are like that. When I elected to place a wireless-controlled Marinco spotlight at that location, the old light fixture was trashed in favor of separate LED side lights stuck on the sides of the anchor pulpit.

I had that Perko junk mentioned by the OP on my GB42 and replaced them with LED units there too. Just make sure the name boards are parallel to the keel and mount the LEDs such that the beam clears whatever wood is aft of it, or cut the wood down to size.

Theoretically, your close up "blind spot" directly ahead will only be the approximately 9-10 foot width of the deck-house structure, but in practice less.

Once while conducting a vessel safety inspection on a boat with the combined light on the underside of the pulpit, I found the lens installed upside down giving green light to port and red to stbd!

 

[nhfred]

If you look at the history of the COLREGS you will see previous regulations stated that the sidelights needed to cover only 90° from dead ahead. When they updated the regulations they changed that to the current angle of 112° from dead ahead, or 22.5 degrees abaft of the beam. This is why the older lights are only angled at 90°.

 

[DDW]

I was following a large excursion boat in thick fog through Toronto inner harbor one night, it was displaying flashing red and green lights. I could not figure out what that meant. Finally got close enough to see that it was the disco ball on the upper dance deck. I'm not sure how the authorities overlooked that.....

 

[rgano]

Since 1965 when I first was required to study and adhere to the COLREGS, I never remember any version of them saying anything other than:

“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."

Now truth be told, back in 1965 and for some years thereafter, the older nautical term of "10 points" was used to describe that arc, a single point being 11.25 degrees. So perhaps that is where your confusion about the arc being only 90 degrees came from. But 90 degrees never happened.

 

[wkearney99]

I was following a large excursion boat in thick fog through Toronto inner harbor one night, it was displaying flashing red and green lights. I could not figure out what that meant. Finally got close enough to see that it was the disco ball on the upper dance deck. I'm not sure how the authorities overlooked that.....

One of the tour boats out of Annapolis (Lady Anna?) had much the same thing a few weeks ago. Band on the top deck and lots of lights. Granted, it was a clear night on the calm waters of the Severn, but I don't recall Regs exempting that...

 

[wkearney99]

While regs dictate certain degrees of visibility, I had a friend's boat just ahead of us coming home on a moonless night. His red/green nav lights cast a fair amount to stern. This make it convenient to just keep his lights centered to follow his path. Now, I know it's wrong, but it helped quite a lot that night!

 

[rgano]

Just so you who have experienced confusing lights from tour and ferry boats don't think you are alone, the Navy has had its own issues with aircraft carrier lighting. There have been a few deadly carrier-versus-escorting destroyer collisions which included largeloss of life as well as sinking on the destroyer side in part because the destroyer's bridge watch could not distinguish the larger ship's navigation lights through the blaze of flight deck and hangar deck lighting. You would think that a destroyer bridge and CIC watch team with all those people looking at radar scopes and the dedicated lookouts would help prevent that sort of disaster, but they did not, and at the last moment when whoever had the conn that night could not tell which way to make a last-second turn away. These collisions I speak of are quite apart from the recent destroyer-merchant ship collisions. Eventually, the Navy spent a lot of money to build masts forward of the island structures of its carriers to place the forward masthead light well forward of the aft masthead light which remains up on the island. This gives a much enhanced indication of the carrier's heading at night. I think other mods were made to the sidelights to make them more visible. By contrast, destroyers run completely darkened with the exception of their navigation lights.

 

[psneeld]

A lot of merchies too can be difficult to pick out running lights.....

Some of the worst can be cruise ships....

 

[markpierce]

A lot of merchies too can be difficult to pick out running lights.....

Some of the worst can be cruise ships....

Yes, it takes a little effort to pick out the running lights, but at least the ships are well lit and visible.

 

[Where Seagulls Dare]

I need new lenses for my port and starboard lights. Does anyone have a picture and size of the lenses handy - I am currently a long way from the boat. Many thanks.

 

[Comodave]

Welcome aboard. There are hundreds of different nav lights out there without much more information your question is impossible to answer, sorry.

If you could post a photo it might help. I always take photos of things that I am working on. The farther the boat is from home the more photos I take. I am lucky now because in the summer the boat is 75’ from the back door but in the winter it is 3 miles so more winter photos.

 

[rgano]

I need new lenses for my port and starboard lights. Does anyone have a picture and size of the lenses handy - I am currently a long way from the boat. Many thanks.

Get the unitary LED side lights and forget about crazed and faded lenses forever.