Aftermarket LED for Nav Lights--DON'T

[SailingHarmonie]

I was delivering a new-to-them sailboat with a customer last week. There was an obvious issue with the deck level navigation lights. We could clearly see the sidelights from the cockpit. Clearly something was wrong for lights whose visibility angle should only be 22.5 degrees behind the beam. The assumption was the mounting bracket was bent, or inappropriate, or something.

When we were doing our post delivery inspection, it turns out the bracket was fine, and so were the fixtures. So what was the problem?

This was a pair of AquaSignal Series 40 lamps designed for a festoon style tungsten bulb with a single, vertical, filament. The bulb had been replaced with an aftermarket LED bulb specifically sold for use in "nav lights". The light emitting part of this bulb is at least 100 times larger in diameter than the fine filament of the bulb the fixture was designed for, making a total mess of the angles with large amounts of spill over both around the bow, and back toward the stern.

Why is this a problem? If you can see BOTH red and green lights from your boat, you would know that the oncoming vessel is pointed very close to directly at you, and make your collision avoidance decisions based on that. Except on this boat, the red/green overlap on the bow was almost 45 degrees, just because of installing the wrong bulbs.They could make a significant turn to alter course, and STILL show you both red and green side lights.

In addition, when the fixtures were disassembled to put the right bulb in, the internal metal parts crumbled away from corrosion. Filament fixtures are at best, poorly sealed, and they will typically fail long before the LED. You spend the extra money for the LED bulb and you don't really get full use of it before the fixture fails. Fixtures that were designed for LEDs are typically potted and fully sealed, and they will allow the LED to life a long and happy life, with proper light brightness, color, and visibility angles.

Remember, the Coast Guard approval for your fixture, is ONLY valid for the bulb that was used to do the tests. If you are buying a bulb other than the exact one that came with the fixture, ask the seller if the combination has been USCG approved. If not... DON'T buy it!

[wholybee]

That is interesting information. I use Dr. LED bulbs, and I know that they sell bulbs to work with specific fixtures. And they have bulbs that are mechanically the same, but have difference elements to account for differences in fixtures. For example, some have the LED lights reflecting off mirrored lenses so that the emitted light is properly aligned with the Fresnel lens cover of the fixture to get the correct pattern. For an all around bulb, they have one for white, one for red/green, and one for red/green/white, which while all "White" light have slightly different wavelengths in different sectors (visible to the eye if you look closely at the lit bulb.)

Anyway, your observations are interesting and valid. But I don't think a sweeping "don't use LED bulbs" is 100% correct. Use the correct bulb.

When the time comes for me to replace my fixtures (which is still going to be a while, given the condition they were in during my last inspection) I will be purchasing fixtures made for LED bulbs.

[kapnd]

LED festoon bulbs are no improvement over the incandescence bulbs, they’ll suffer the same corrosion problems due to poorly waterproofed housings.
I’ve learned to appreciate the sealed LED fixtures, and have had no problems with them.

[barcoMeCasa]

I´ve made a few from scratch, anchor light obviously fine but with the viewing angle of the LED's the steaming light needed quite a long baffle to get the cutoff more accurate. Still preety common to see both red & green for a hile crossing a bow, suspect a lot of the units in chandlers aren't that great anyway.

Very successful home made jobs though, anchorlight has been on every night shining bright for years now. potted with epoxy in some 40mm plastic pipe with Cree leds.
https://oshwlab.com/paddyb/anchorlightmaster_copy

[rslifkin]

Originally Posted by barcoMeCasa

Still preety common to see both red & green for a hile crossing a bow, suspect a lot of the units in chandlers aren't that great anyway.

A lot aren't necessarily installed carefully enough either.

[barcoMeCasa]

Originally Posted by rslifkin

A lot aren't necessarily installed carefully enough either.

Likely, or been bashed along the way. Not a relaxing thing to see, both red / green at the same time 😲😊

[ggray]

Originally Posted by rslifkin

A lot aren't necessarily installed carefully enough either.

That's the truth, and it can be the boat manufacturer that does it.

Had a Scout power boat with red and green placed where you could see both colors for a 60 degree sector in front of the boat. Not good.That left 30 degrees each side where no light was seen. Not good either.

I had a very hard time explaining to Scout what the problem was and how I thought they would be liable if it caused a collision. The CG requirements are quite precise.