Why do the lights look wrong? - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > General Interest > General Discussion (sailing related)
 Not a Member? 


Reply
 
LinkBack Thread Tools
  #1  
Old 09-05-2008
davidpm's Avatar
Senior Member
 
Join Date: Oct 2007
Location: Madison
Posts: 3,698
Thanks: 166
Thanked 38 Times in 31 Posts
Rep Power: 7
davidpm is on a distinguished road
Why do the lights look wrong?

I just went through the Race between Little Gull and Valiant last weekend and did a little post Mortem chart work.

We were exactly in the middle and we both saw a light that was exactly where Little Gull (2) 15s 91ft 18M Horn was expected.

The problem was that the light seemed to us to be Blink, off 5 sec, blink, off 10 sec, blink off 5 sec, blink off 10 sec (repeat)

I was expecting blink,blink off 15 sec (repeat)
How is this light sequence supposed to be read?

Last edited by davidpm; 09-05-2008 at 10:13 PM.
Reply With Quote Share with Facebook
  #2  
Old 09-05-2008
hellosailor's Avatar
Plausible Deniability
 
Join Date: Apr 2006
Posts: 10,616
Thanks: 2
Thanked 88 Times in 86 Posts
Rep Power: 10
hellosailor has a spectacular aura about hellosailor has a spectacular aura about
David, that area can be very confusing with visual clutter from all the islands AND the CT shoreline. You don't say which way you were going, but I'd look at the charts again to see if there was anything "behind" the light that you may have mistaken for addiitonal flashing from the same place.

The first time I came up into the Sound from the Atlantic, I finally gave up and road the depthsounder up the deep channel. Never seen so much background clutter in all the wrong places.

Check out chapter 5 of Bowditch:
http://www.irbs.com/bowditch/pdf/chapt05.pdf (page 68, page 6 in this pdf file, Type 4.2)

Your math is right, unless the light was recently changed. (Not likely for a long-established light.)

Last edited by hellosailor; 09-05-2008 at 11:15 PM.
Reply With Quote Share with Facebook
  #3  
Old 09-05-2008
Boasun's Avatar
Senior Member
 
Join Date: Feb 2007
Location: New Orleans, LA
Posts: 3,064
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 9
Boasun will become famous soon enough Boasun will become famous soon enough
Check your Light List for Little Gull Light. The entry for that light will give you the light sequence.
I would do it, but my Light list for that area is in my class room and not here at home. But if you don't have one, you can down load one for your area for naught at nga.mil, Then go to the maritime product section of their menu.
__________________
1600 Ton Master, 2nd Mate Unlimited Tonnage

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Maritime Instructor
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

S/V Rapture
Reply With Quote Share with Facebook
  #4  
Old 09-06-2008
davidpm's Avatar
Senior Member
 
Join Date: Oct 2007
Location: Madison
Posts: 3,698
Thanks: 166
Thanked 38 Times in 31 Posts
Rep Power: 7
davidpm is on a distinguished road
Quote:
Originally Posted by Boasun View Post
Check your Light List for Little Gull Light. The entry for that light will give you the light sequence.
I would do it, but my Light list for that area is in my class room and not here at home. But if you don't have one, you can down load one for your area for naught at nga.mil, Then go to the maritime product section of their menu.
I get this from the light list
19830
Little Gull Island Light 41 12 23 N
72 06 25 W

Fl (2) W
15s 91 18 Gray granite tower, attached to
red dwelling on pier.
Emergency light of reduced
intensity when main light is
extinguished.

HORN: 1 blast ev 15s (2s bl).
Reply With Quote Share with Facebook
  #5  
Old 09-06-2008
davidpm's Avatar
Senior Member
 
Join Date: Oct 2007
Location: Madison
Posts: 3,698
Thanks: 166
Thanked 38 Times in 31 Posts
Rep Power: 7
davidpm is on a distinguished road
[quote=hellosailor;364142]
Check out chapter 5 of Bowditch:
http://www.irbs.com/bowditch/pdf/chapt05.pdf (page 68, page 6 in this pdf quote]

I found this quote
At short distances, some of the brighter flashing lights
may show a faint continuous light, or faint flashes, between
regular flashes. This is due to reflections of a rotating lens
on panes of glass in the lighthouse.
Reply With Quote Share with Facebook
  #6  
Old 09-06-2008
Boasun's Avatar
Senior Member
 
Join Date: Feb 2007
Location: New Orleans, LA
Posts: 3,064
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 9
Boasun will become famous soon enough Boasun will become famous soon enough
Quote:
Originally Posted by davidpm View Post
I get this from the light list
19830
Little Gull Island Light 41 12 23 N
72 06 25 W

Fl (2) W
15s 91 18 Gray granite tower, attached to
red dwelling on pier.
Emergency light of reduced
intensity when main light is
extinguished.

HORN: 1 blast ev 15s (2s bl).
Okay down loaded Volume 1 of the light lists. And looked it up.
Double check the timing you have observed and send the light sequence to the USCG, Your Notice to Mariners will have the address. Give the index number, light's name and so forth. And note the lighting sequence.
Usually they will publish your name & Vessel's name in the next NTM. At least they use to.
__________________
1600 Ton Master, 2nd Mate Unlimited Tonnage

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Maritime Instructor
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

S/V Rapture
Reply With Quote Share with Facebook
  #7  
Old 09-06-2008
Boasun's Avatar
Senior Member
 
Join Date: Feb 2007
Location: New Orleans, LA
Posts: 3,064
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 9
Boasun will become famous soon enough Boasun will become famous soon enough
2006 Light Lists - USCG Navigation Center
Use this address to down load the Light List of the area you are in of the USA. The charge is just your time on the computer. Otherwards the cost is NADA... which is nice.
Oh! Minor detail the Light List are now 2007 corrected to 27/07
__________________
1600 Ton Master, 2nd Mate Unlimited Tonnage

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Maritime Instructor
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

S/V Rapture
Reply With Quote Share with Facebook
  #8  
Old 09-06-2008
hellosailor's Avatar
Plausible Deniability
 
Join Date: Apr 2006
Posts: 10,616
Thanks: 2
Thanked 88 Times in 86 Posts
Rep Power: 10
hellosailor has a spectacular aura about hellosailor has a spectacular aura about
Boasun, the background clutter in that area can be extreme. Reporting it as a malfunction might be a bit premature. There is enough commercial traffic, including local commercial traffic, that it would probably be reported promptly if it was indeed out of order. (By someone familiar with the scene.)
Reply With Quote Share with Facebook
  #9  
Old 09-06-2008
Boasun's Avatar
Senior Member
 
Join Date: Feb 2007
Location: New Orleans, LA
Posts: 3,064
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 9
Boasun will become famous soon enough Boasun will become famous soon enough
What he is noticing is the light sequence. And that should be noted in the light lists... And double checking on that, isn't that hard. Have done it many times in various areas of our great coast lines.
__________________
1600 Ton Master, 2nd Mate Unlimited Tonnage

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Maritime Instructor
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

S/V Rapture
Reply With Quote Share with Facebook
  #10  
Old 09-06-2008
davidpm's Avatar
Senior Member
 
Join Date: Oct 2007
Location: Madison
Posts: 3,698
Thanks: 166
Thanked 38 Times in 31 Posts
Rep Power: 7
davidpm is on a distinguished road
Quote:
Originally Posted by Boasun View Post
2006 Light Lists - USCG Navigation Center
Use this address to down load the Light List of the area you are in of the USA. The charge is just your time on the computer. Otherwards the cost is NADA... which is nice.
Oh! Minor detail the Light List are now 2007 corrected to 27/07
Yes that is where I got the light information I posted.
The chances of this light which has been at that location for over 200 years is malfunctioning is remote. It is almost certainly me.

I interpret Fl (2) 15 as flash, flash, 13 sec dark.
What I saw was flash, 5 sec dark, flash, 10 sec dark.
Notice that it adds up to 15 seconds.

This is where I got my light list:
2006 Light Lists - USCG Navigation Center
There are thousands of lights around plus that reflected thing Bowditch mentioned and something was happening. We knew where we were I'm just a little distressed it was so hard to identify the lights properly.

A couple of miles away at Cerberus Shoal the chart says fl G 4sec.
To me that is supposed to be flash, 3 sec dark.
What I saw was flash, 3 sec dark, flash 8 sec dark.
In other words I was missing every other flash.

It was over a 40 hour trip and all the other lights were fine even a Morse A which I had not seen before but was neat.

I'll probably call the coast guard, they seem pretty tolerant of dumb questions.
Last year I called and got a really nice guy from another district. I wanted to know why half the lights are (R 4sec). He thought my question was humorous as he was a station chief and that was one of his pet peeves too. He thinks back in the day when this stuff was expensive their was a sale on 4 sec flasher circuits.

Last edited by davidpm; 09-07-2008 at 12:06 AM.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Definitions of lights on control panel - S2 8.0 overholtzer S2 4 09-03-2007 01:47 PM
Bow and Stern Running Lights Duke 7184 Morgan 1 11-14-2006 06:54 PM
Light Lists, Lighthouses, and Visible Ranges Jim Sexton Seamanship Articles 0 06-19-2003 08:00 PM
Light Lists, Lighthouses, and Visible Ranges Jim Sexton Her Sailnet Articles 0 06-19-2003 08:00 PM
Running Lights SailNet Seamanship Articles 0 06-21-2002 08:00 PM


All times are GMT -4. The time now is 03:04 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.