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LED anchor light
Posted: Wed May 12, 2004 6:58 pm
by Larry Read
Chris
Thanks for the tip on the wire size. I agree with you completely regarding the integrity if the mast. It appears the foams primary purpose is to create watertight compartments. After the wire is run, I will foam the first inch or two of the channel and as well as the area the channel exits the foam bellow the spreaders thus completing the seal. The only weight gain to the mast is the PVC and the wire.
As to the LED anchor lights, any hints on where to look for them?
Larry
Posted: Wed May 12, 2004 8:04 pm
by Dimitri-2000X-Tampa
Here's a novel idea to keep your mast from filling with water....don't get knocked down!
A masthead light covers only 20 points or 225 degrees total.
Chip, are you sure about that? I just looked at these Davis Megalights the other day at WM and they sure look like 360 degree anchor lights to me. I actually bought the utility (portable) version as I don't have an anchor light. The output is pretty low, but I guess that is why they use so little power.
One thing to note on sailnet, there is a review of the Davis light that says it is flakey and sometimes does not come on...indicating that the photocell may not always work right. Any of you had that problem or had the lights long enough to endorse their reliability?
Anchor Light
Posted: Wed May 12, 2004 9:07 pm
by Jack O'Brien
I have both the Davis Mega Anchor light with the photocell and the utility light. Never a problem with either one. Haven't used them much.
Posted: Wed May 12, 2004 10:20 pm
by Duane Dunn, Allegro
The davis lights are 360 degree lights. The light Chip is refering to, the masthead light, is the one the factory installs about 10' up the front of the mast. This is a navigation light for use under way at night. If you are sailing you turn on your red and green bow lights and your stern white light at night. This indicates a sailboat which always has right of way over a powerboats. If you are powering you add the masthead light on the front of the mast to the bow and stern lights. This indicates you are a power boat and must follow the normal motoring right away rules. As Chip mentions, I prefer to call this light a "Steaming" light so it is not confused with the all around top of the mast anchor light used when not under way.
As we discussed elsewhere, nothing requires that the anchor light be at the top of the mast. It simply has to be an all around 360 degree light, hung failrly high, visible for 2 miles, and not obscured for more than a total of 6 degrees of arc.
I use the Davis light hoisted as far up my backstay as the cord will reach.
Here is a link to a nice LED all around light that would work well at the top of the mast.
All Around LED light. Here is
Another
Posted: Thu May 13, 2004 11:57 am
by Chip Hindes
Duane wrote:The davis lights are 360 degree lights. The light Chip is refering to, the masthead light, is the one the factory installs about 10' up the front of the mast.
Yes and no. The light I was referring to was the light Harry said he was using and the one pictured in the link he provided: the Davis Masthead Megalight. If you look at the picture in the link, it certainly appears that it's intended to be mounted as a Masthead light by the Coast Guard definition, and is not a 360 degree light.
It would certainly make sense that Davis would manufacture other Megalights which were intended for use as Anchor or All-Round lights, but if so they should be called that. It's wrong to call a 360 degree light a Masthead light, because a 360 degree light would specifically be not legal for Masthead use.
Obviously, a 360 degree light mounted at or near the top of the mast could serve as either an Anchor light, or when motoring as an All-Round light in lieu of Masthead and Stern lights.
You still have the question as to whether the required 2nm visibility is legally and practically adequate.
Posted: Fri May 14, 2004 5:01 am
by Harry van der Meer
Chip, the Mega Light
http://www.sailnet.com/store/item.cfm?pid=11449 is a 360 degree light and is intended to be mounted on top of the mast as an anchor light. The bracket has even an allowance for installation of a windex wind meter.
There is one concern with this light however and that is that it is not Coast Guard approved. This could get you in trouble if you were anchored in a location where an anchor light is required. I confess, I have not read the rules, but I understand from a good boating friend that an anchor light is not required if you anchor in a designated anchor area.
Beg's the question however, why go through the trouble of installing an anchor light if it is not CG approved. I found however, that many of the anchor lights on the market make no reference to CG approval.
I was more concerned about power consuption. Using the "bright bulb" of the Mega light, consumption is 320 mA (per the light's manual). which is a little less than half a regular 10 W bulb. I am not sure if the concerns expressed about visibility of this light are with the 110 mA ("energy efficient bulb" - what ever that means - just low lumen output??) or with the "bright bulb". I also liked the fact that the Mega light has a photocel included.
The fresnel lens of the Mega Light seems to focus the light. With the "bright bulb" installed, the light seems to be as bright as other anchor lights I have seen (not very scientific however).
Posted: Fri May 14, 2004 8:58 am
by Chip Hindes
OK. I guess it only looks like the Davis Masthead light is what they said it was. I’ll just blame Davis and/or Sailnet for not knowing the difference between a Masthead light and an All Round
I wouldn’t be too concerned about “Coast Guard Approved.” Does anyone know if there is a process by which a company can obtain actual Coast Guard approval for their lights? More likely, “Coast Guard Approved” is marketing doublespeak for “We‘re pretty sure they meet Coast Guard requirements.” In my experience, Coasties are pretty reasonable about these sorts of things, and they’re not gonna board your vessel and order you to drop your mast so they can check if your anchor light is Coast Guard approved. Any Coasties lurking out there?
In perusing the 4-5 pages of lights in the West Marine catolog, I notice only a single Hella brand light which is stated to be Coast Guard Approved. All of the Perko LED lights say “Meets Coast Guard and ABYC standards.” I wonder if that means the non-LED lights don’t. Aqua Signal, whose Series 20 lights are about the cheapest and (surprise) the ones which I believe are standard on most late model Macs also make some pretty expensive lights, but they are totally silent on the matter.
I believe when it comes to incandescent lights, in general light output is pretty much directly related to power consumption. A 5W (420ma) light is half as bright as a 10W(840ma), your “bright bulb” Davis is 4W (320ma) about 1/3 as bright, etc. Manufacturers can maximize the effect of a given amount of raw light through clever lens design, but everybody pretty much already knows how to do this, so the actual difference between competing lights of a given wattage is small. BTW, the standard Aqua Signal Series 20 lights on the Mac are all 5W, as is the same series All Round light I’m using as an anchor light; so the difference between that and the 320ma Davis “bright bulb” is not much. The Davis “energy saver” bulb proves the above by a simple logical exercise, otherwise the entire concept is bogus. They could just as truthfully advertize the two bulbs as “low light” and “energy waster.”

Scientific testing would be useful, but my feeling is that if you do a side by side comparison and the brightness appears equal, it probably is. I believe however, that apparent brightness is a function of distance squared, so that a subtle difference when viewed up close could be significant when viewed from the requisite 2nm.
LEDs are different in that they put out a lot more light per Watt. The problem for me is it’s difficult to justify spending $100 or more each to replace existing lights that, as they stand right now, draw less than amp. I think I can live with 5 Ah per night and direct my energy saving efforts elsewhere, or for the same money, buy a bigger battery (or two) which will be way more useful overall (oh the horror of it all!)
There's no particular reason I can see that the LED lights should be so expensive. The LEDs themselves and the circuits required to power them are more expensive, but not enough more to justify the huge differential. If (when) get the cost down to something reasonable, or if we could find the fairly inexpensive LED retrofit bulbs which both fit and don’t compromise light output, I might think again.
Sorry this is so long.
Posted: Fri May 14, 2004 6:32 pm
by craiglaforce
I did a search a while back on light requirements. I think the anchor light had to be at least 5-7 candlepower if memory serves to meet the visabilty requirements. As long as it was this bright, that was the only requirement. It could be a kerosene lantern, electric light or anything else as long as it was 5-7 candlepower. I don't recall the exact number. It was in the CFRs (code of federal regs). THey had a nice little equation that related atmospheric transmissivity and candlepower to visable distance. You would think they would post the candlepower of all these lights that are being sold for nav purposes.
Posted: Fri May 14, 2004 9:51 pm
by Larry Read
Thanks for the source for the LED. I have to agree with Chip when it comes to spending the extra on something I will not use very often. I just received a Hella Marine 10 watt ($15.99 at West Marine #598458) and FYI it comes with certificates of Test Confirmations for 7 different countries including Italy. Ive heard a Mac can easily make it to Hawaii but anyone up for Europe? Ive got the light!
If this is like most technology, we will look back in three years and be asking where we can buy a replacement incandescent bulb?
Larry
led nav lights
Posted: Sun May 16, 2004 10:42 am
by norbert
i think since long time about led bulbs for my navlights to save energy but did not yet find a feasible and affordable solution.
deep creek design has what i'd like to use, but see the price!
i also thought about making my home made bulbs out of a old bay15d socket and a cluster of white leds, but there are several problems.
leds work at about 3v (different for each led type). even if you connect them in serie to have a 12v load, they are less tolerant to voltage fluctuation than traditional bulbs. your power system delivers 11.5 to 14.5 volts depending of the charge state of your battery, the motor running or not or shore power connected. this variation is more than leds will accept. so you have to integrate a voltage stabilization. as deck plug and wiring resistance will contribute ti this the sabilization should be in or near the bulb.
other problem: white leds usually have a narrow lighting angle (about 30 degrees max). so you need a cluster of at least 12 to obtain a 360 degree light. not easy to build in the restricted space of a navlight!
but i'm still working on that!

Posted: Sun May 16, 2004 1:01 pm
by Don T
Hello:
I've been meaning to design an LED system. The trick to brightness is pulsing max current for a short period at around 1 khz. This way the LED is at full brightness but has an off period to dissapate heat. At 1 khz it appears to the eye to be on all the time. They are very bright with a low current draw and long life (100x). I could see a ring that mounts around the top of the mast with the LEDs firing in groups or sequentially. The whole system might draw 50ma. LEDs are current driven devices so a PWM system could control the current output and the sytem would operate anywhere between 6V and 24V.
Luxeon Star I in DIY anchor lite
Posted: Sun May 16, 2004 3:50 pm
by ronacarme
(1) See Trailersailor bulletin board 11/2/03 posts re led anchor litese.g. search "all" keywords option with keywords "tanis led anchor" for many posts re led anchor lites.
(2) Since my post in that string I did a little further work. I thot I had posted the result, but can't find it, so I may post an update there (where there is a long term archive).
(3) Briefly, it comprises a Star I LED side emitter driven at rated 1.2 watt by a constant I source drawing about 2.7 watts from a 12.1 V supply and with its mostly radially emitted lite further narrowed to the radial plane by a scrounged Fresnel lens. casual testing suggests possible 2 nm visibility but more rigorous testing across the water awaits putting in the boat.
Posted: Sun May 16, 2004 5:52 pm
by Joe 26M Time Warp
Hello everybody.
Don T wrote:I could see a ring that mounts around the top of the mast with the LEDs firing in groups or sequentially. The whole system might draw 50ma.
Hey cool idea, I wonder how many LED's are in one of these
http://www.orcagreen.com/Anchor.cfm
I was wondering if anyone craming pipes and drills through the mast have damaged or replaced the mast light wire. I know I did, and I replaced all the 12 volt wires with #12 thhn. Part of the logic was not having any faith in that "approved" marine duplex, but I pulled 3 to the top; anchor set and spare, the spare also loops at the mast light. This setup gives me a wire to pull anything added later with, as well as some prewired backup.
I'm keeping the old one but will switch to the redesigned mast pivot on #358.
Luxeon Emitters
Posted: Sun May 16, 2004 8:06 pm
by Duane Dunn, Allegro
That fixture has the latest generation LED, a Luxeon Star. They are 10 times brighter that the previous single high output LEDs. They are just starting to appear in the flashlight and headlamp world. They come in 1 watt, 3watt, and 5 watt versions.
Luxeon Emitters
They are without a doubt the future of lighting. You can match the output of normal bulbs without resorting to multi LED clusters. They can also be focused with lenses much easier.
Re: Anchor Lights and Drilling a Mast Channel
Posted: Thu Nov 03, 2011 3:34 am
by euhero987
I know this maybe a stupid question but I have to ask this to make sure. Is LED anchor lights really reliable?