[Public-List] USCG Alert re sailboat nav lights' vertical angle

Sat Apr 6 14:56:33 PDT 2019

All of the navigation lights I have seen on different boats has a fresnel lens that focus,s the light source of a incandescent lamp to the centre of the lens.  Replacing an incandescent bulb with a LED will not focus the light into the centre point of the lens thus giving a 2mile range.  This why they are not legal as navigation light fixtures, fixtures designed with LED,S will be legal.

John Boor

Sent from my iPad

> On Apr 6, 2019, at 3:58 PM, George Dinwiddie via Public-List <public-list at lists.alberg30.org> wrote:
> 
> What is the beam angle of the LED lamp? The angle of the incandescent is 360 degrees.
> 
>> On 4/6/19 3:51 PM, Michael Connolly via Public-List wrote:
>> George,
>> These are my original navigation lights on the sides of the coach. Inside there is a glass lens most of which is covered by the bronze housing. The incandescent lamp Ge 9002 is about the size of a dime. Supposed to be two mile visibility. The single LED which fits the same socket is also rated at two mile visibility. I was assuming that the glass lens was responsible for the dispersion of the light. I am not changing the angle or position of the lamp fixture. What do you think? Newer Alberg 30's have these lights near the bow mine are back on the forward sides of the coach.
>> Michael #133
>>> On April 4, 2019 at 11:02 PM George Dinwiddie <gdinwiddie at alberg30.org mailto:gdinwiddie at alberg30.org > wrote:
>>> 
>>> 
>>>     No, because LED lamps have different angles of illumination than incandescent. A single LED has a quite narrow beam. Lamps are designed with multiple LEDs and diffusers to create a wider beam.
>>> 
>>>     George
>>> 
>>>     Sent from a primitive pocket computer. Please assume all errors are due to that.
>>> 
>>>         > > On Apr 4, 2019, at 22:45, Michael Connolly via Public-List <public-list at lists.alberg30.org mailto:public-list at lists.alberg30.org > wrote:
>>>> 
>>>>         George,
>>>>         I am assuming that if I am just changing the lamp and not the entire fixture that I am still good. Unless the requirements have changed significantly since 1966.
>>>>         Michael
>>>> 
>>>>             > > > On April 4, 2019 at 5:47 PM George Dinwiddie via Public-List <public-list at lists.alberg30.org mailto:public-list at lists.alberg30.org mailto:public-list at lists.alberg30.org mailto:public-list at lists.alberg30.org > wrote:
>>>>> 
>>>>> 
>>>>>             Or
>>>>>             https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/0219.pdf
>>>>>             so the link doesn't get broken.
>>>>> 
>>>>>             On 4/4/19 4:38 PM, David Tessier via Public-List wrote:
>>>>> 
>>>>>             >> https://www.dco.uscg.mil/Portals/9/DCO Documents/5p/CG-5PC/INV/Alerts/0219.pdf
>>>>> 
>>>>>                 > > > >
>>>>>>                     > > > > > --
>>>>>>> 
>>>>>>>                 > > > >
>>>>>>             > > > ----------------------------------------------------------------------
>>>>>             When I remember bygone days George Dinwiddie
>>>>>             I think how evening follows morn; gdinwiddie at alberg30.org mailto:gdinwiddie at alberg30.org mailto:gdinwiddie at alberg30.org mailto:gdinwiddie at alberg30.org
>>>>>             So many I loved were not yet dead, http://www.Alberg30.org
>>>>>             So many I love were not yet born. also see:
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>>>>>             ----------------------------------------------------------------------
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> -- 
> ----------------------------------------------------------------------
>  When I remember bygone days                         George Dinwiddie
>  I think how evening follows morn;            gdinwiddie at alberg30.org
>  So many I loved were not yet dead,           http://www.Alberg30.org
>  So many I love were not yet born.                          also see:
>               'The Middle' by Ogden Nash     http://idiacomputing.com
> ----------------------------------------------------------------------
> 
> 
> 
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