Why do the lights look wrong?

[davidpm]

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?

[hellosailor]

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.)

[Boasun]

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.

[davidpm]

Originally Posted by Boasun

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).

[davidpm]

[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.

[Boasun]

Originally Posted by davidpm

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.

[Boasun]

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

[hellosailor]

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.)

[Boasun]

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.

[davidpm]

Originally Posted by Boasun

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.