[Rhodes22-list] LED Navigation Lights -- specifications

[Robert Skinner]

Folks,

LED nav lights for sailboats need a wider dispersion 
than just the horizontal plane.  As we are often heeled 
over 10 degrees or more for extended periods, if a nav 
light does not cover an arc of 15 degrees above and 
below the horizon throughout its intended bearing range, 
it may not be visible from the side.

When you look at LED nav lights for your sailboat, 
check carefully for this spec.  It is often omitted.  
Many LED nav lights are designed with a lesser arc of 
visibility above and below the horizon, as might be 
appropriate for a power boat.

In my reading of vendor literature, even with the wide 
dispersion type of LED, the power consumption for the 
same spherical sections of output visibility would be 
less.

When I replace my lights, I'll be going with LEDs.  I
think it will pay off in the long run in labor, total
service life, and power consumption, even with the 
still-high initial cost.

/Robert Skinner
------------------------------------------------------
John Lock wrote:
> ...
> At 07:35 PM 7/31/2006 -0400, you wrote:
> >Now that's interesting.  This was also true on the other LED
> >choices.  I wonder that they must go through a beaucratic approval
> >process - probably doing all of that now.  Thanks for the heads-up,
> >Bill.  They identify them as equivalent to the approved non-LED
> >bulbs, suggesting for nav use also.
> 
> Actually, I think there is is a very good reason for that.  LEDs, by
> nature, give off a very narrow cone of light, as compared to
> incandescent.  Which means if you place one on your masthead, most of
> the light will be shining up, not out where you want it.  Some of the
> replacement bulbs may actually be banks of several LEDs arranged to
> throw out light to the sides or placed under some kind of dispersing
> lens.  However, if you have a bank of several LEDs to get the
> coverage area you want, you may not be saving much energy over a standard bulb
> 
> You can get some good information comparing various lighting sources
> at http://www.otherpower.com/otherpower_lighting.html
> 
> Cheers!
> 
> John