NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Message:αβγ
Message:abc
 Add Images & Files Posting Code: Name: Email:
Re: Nav light colors and ranges
From: Rodney Myrvaagnes
Date: 2003 Oct 13, 23:58 -0500

```The tricolor only uses one filament. The vertically-displaced red and
green probably four, since they are on each side of the mast.

On Mon, 13 Oct 2003 23:42:34 -0400, Jared Sherman wrote:

>With all the talk of light ranges and alternates I made the mistake of
looking back in COLREGS and found some things to wonder over. I put it to the
list for comment and note as usual I am not licensed to practive mathematics,
don't accept any numbers I present as being correct.
>
>COLREGS gives examples of lamp brightness as:
>1nm     0.9cp
>2       4.3
>3       12
>4       27
>5       52
>6nm     94cp
>
>and for vessels under 12m requires a sidelight range of only 1 nm (0.9cp)
>and all other lights 2nm (4.3cp)
>
>for 12-50 meters,
>all others 2nm (4.3cp) including all-around lights.
>
>I note this because it would mean a sailboat 12-50m, using red/over/green all
around lights would need a total of 8.6cp with that lighting scheme--but 12cp
with a masthead tricolor light. So here the alternate lighting saves 25% on
power needs.
>
>For a boat under 12m it would mean 8.6cp instead of 4.3cp, actually doubling
power consumption on the mast.
>
>Pros and cons, it would seem. And I have no idea how the lamp manufacturers
match bulbs for this criteria, I'd expect them to use "stock" bulbs so
perhaps with tungsten bulbs it is simply 10W vs 20W and devil take the
details.
>

Rodney Myrvaagnes J36   Opinionated old geezer

Eagles may soar, but weasels don't get sucked into jet engines.

```
Browse Files

Drop Files

Join NavList

 Name: (please, no nicknames or handles) Email:
 Do you want to receive all group messages by email? Yes No
You can also join by posting. Your first on-topic post automatically makes you a member.

Posting Code

Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
 Email:

Email Settings

 Posting Code:

Custom Index

 Subject: Author: Start date: (yyyymm dd) End date: (yyyymm dd)