Where do you put your Anchor Light

[RupertW]

Without formal testing (which is expensive and not practical unless you are planning to sell the lights) it is difficult to be 100% sure if a light will meet the legal requirements for brightness. However, Bebi published a paper a few years ago on what type of LEDs would be required to be bright enough to pass the 2nm test. With the best 5mm Nichi LEDs that were available at the time.

The conclusion, from memory, was that a minimium of fifteen of the best 5mm Nichi LEDs were the minimum required to meet the standard. These also needed be driven with the correct regulated supply at their rated voltage. For comparison, most garden lights have one or two 5mm LEDs of dubious quality (although the brightness of LEDs improves each year) driven by an unregulated power supply. There are alternatives to 5mm LEDs, typically using a single high powered LED with an optical system to distribute the light, but the paper did not look at the requirements for these options.

The other test is to look at power consumption of your light. Most commercial 2nm approved anchor lights consume about 0.2 A @ 12v. Unless you are buying, or building, a battery operated light which is much more efficient than the commercial anchor lights then to produce the same brightness the light will need to consume roughly the same amount of power.

Assuming they are fully charged, it would take about ten high quality AA batteries to store enough energy to deliver this power for one night. So unless your battery operated light has 10 or more AA batteries (or the equivalent lithium battery) it is unlikely (but not impossible) to meet the brightness standard. This reasonably large power requirement is why battery operated anchor lights can rarely meet the standard. The light can easily have a setting that is bright enough, but on this setting the light will only last a short time. If it is bright enough and it can last all night it needs a large battery bank and few models have this.

That’s really useful as a guide and approximation - each of our two lights has a very good glass all round lens 8 LEDs and 4 AAs which last all night - so in total it’s close to what is needed but individually not. But still very bright half a mile away in good vis.

Will keep looking for better ones to eventually replace ours then.

 

[sailorman]

My copper Davey lantern lasts all night

 

[VicS]

There is no reason why a battery powered light (whether solar powered or not) shouldn't be bright enough with LEDs and you find out quickly whether a fully charged battery will last all night ).

I must look up how you can tell whether a light would be visible at 2nm - it's not just lumens I guess. But the legal bit matters least to me - I would always claim I had the pointless masthead light on if hit. The important bit is being visible (for me both bow and stern) at eye level and with a chance to guage distance and the ends of the boat which two lights really helps with.

There is a formula for calculating the luminous intensity in candelas in Annex I, 7 of the colregs

( 1 candela = 1 lumen / steradian)

A masthead light is defined in the regs as:

a white light placed over the fore and aft centreline of the vessel showing
an unbroken light over an arc of the horizon of 225 degrees and so fixed as to show the light from
right ahead to 22.5 degrees abaft the beam on either side of the vessel.used when under power​

it need only be 1 m above the side lights. It is what we often call the "steaming light"

An anchor light is an alround white light described in the regs :

(a) A vessel at anchor shall exhibit where it can best be seen:
(i) in the fore part, an all-round white light or one ball;
(ii) at or near the stern and at a lower level than the light prescribed in sub-paragraph (i), an
all-round white light.
(b) A vessel of less than 50 metres in length may exhibit an all-round white light where it can best be
seen instead of the lights prescribed in paragraph (a) of this Rule​

Note paragraph (b) says "where it can best be seen" ! It is not required to be at the masthead!

See previous comments ( and Annex I, 9 (b) ) about the extent to which an allround light may be obscured by masts etc and the use of two lights when the requirements for one light cannot be met

 

[noelex]

That’s really useful as a guide and approximation - each of our two lights has a very good glass all round lens 8 LEDs and 4 AAs which last all night - so in total it’s close to what is needed but individually not. But still very bright half a mile away in good vis.

Will keep looking for better ones to eventually replace ours then.

Yes, I think that is a reasonable conclusion and a good way of determining how close to the 2nm legal requirement your light is likely to be, but I stress it is only very approximate.

It is dependent on the exact component used. Many of the battery lights are made inexpensively. If the light has used 800 mAhr AA batteries and lower quality emitters, it could easily be producing half the light output of a model with better batteries and quality LEDs. Then the solar panel (if this is how the batteries are charged) has to be large enough to fully charge the batteries even on duller days.

 

[GHA]

However, Bebi published a paper a few years ago on what type of LEDs would be required to be bright enough to pass the 2nm test. With the best 5mm Nichi LEDs that were available at the time.

The conclusion, from memory, was that a minimium of fifteen (once again from memory) of the best 5mm Nichi LEDs were the minimum required to meet the standard. These also needed be driven with the correct regulated supply at their rated voltage.

Thanks, forgot there was so much on their site when it was around.

And with the magic of the internet wayback machine - it still is

https://web.archive.org/web/20110827094623/http://www.bebi-electronics.com:80/specs.html
https://web.archive.org/web/20110319015643/http://www.bebi-electronics.com/


Interesting how much LEDs have come on, they used :

Off-Axis	Measurement
0˚	Minimum
	Average	14.0
	Typical	16.2
	Maximum	18.6

[TD="colspan: 4, align: center"] NSPW500DS -15˚ 1/2 θ[/TD]

[TD="align: center"] cd [/TD]
[TD="align: center"]lumens/
device [/TD]

[TD="align: right"]9.3[/TD]
[TD="align: right"]2.0[/TD]

[TD="align: right"]3.0[/TD]

[TD="align: right"] 3.5 [/TD]

[TD="align: right"]4.0[/TD]

The cree ones I used building a very similar light based on Bebi a couple years ago - typical 48CD at the same 20mA current (66% of max sustained current). Also the forward voltage seemed much better between LEDs, no real need to match them.

TYPICAL ELECTRICAL & OPTICAL CHARACTERISTICS (TA = 25°C)
Characteristics Symbol Condition Unit Minimum Typical MaximumForward Voltage
VF IF = 20 mA V 3.2 4.0
Reverse Current IR VR = 5 V μA 100
Luminous Intensity IV IF = 20 mA mcd 28200 48000
ChromaticityCoordinatesx IF = 20 mA 0.2895y IF = 20 mA 0.290550%
Power Angle 2θ½ IF = 20 mA deg 15

 

[noelex]

Thanks, GHA. Well found. That is exactly the paper I was remembering.

It is a bit technical, but is interesting reading if you want to make your own anchor light, or are interested in estimating how close the battery light you have purchased would be to passing the minimum 2nm standard.

 

[GHA]

Thanks, GHA. Well found. That is exactly the paper I was remembering.

It is a bit technical, but is interesting reading if you want to make your own anchor light, or are interested in estimating how close the battery light you have purchased would be to passing the minimum 2nm standard.

For reference I just measured mine, 15 x Cree C503D-WAN, 5 parallel stings of 3 LEDs in series with a DIY constant current regulator - 105mA @ 13.6V.

 

[noelex]

For reference I just measured mine, 15 x Cree C503D-WAN, 5 parallel stings of 3 LEDs in series with a DIY constant current regulator - 105mA @ 13.6V.

Well done. That is very efficient.

 

[Graham_Wright]

What about having a flashing light similar to or if not exactly like a navigation mark. I doubt if this would be legal but would certainly confuse all and sundry into slowing right up to identify said light?

That is obviously dangerous and illegal and could cause an accident.

 

[RupertW]

That is obviously dangerous and illegal and could cause an accident.

Agreed but very common and some on here support it

 

[lw395]

For reference I just measured mine, 15 x Cree C503D-WAN, 5 parallel stings of 3 LEDs in series with a DIY constant current regulator - 105mA @ 13.6V.

Those LEDs should have a Vf of 3.2V each typically, max 4V at 20mA

 

[alan_d]

Makes sense to me too . But as I said, the rule I posted applies in Australia
"Anchor light. A white light that shines so it is visible from all around the vessel required when anchored or moored between sunset and sunrise. The best place for this light is usually at the top of the highest mast."
and I am only assuming it applies in other countries. The 6 dg sector seems to be a reasonable compromise, but you won't get away with it here. If in doubts: Just 2 years ago I witnessed a few skippers at the anchorage where I am now (Southport at Gold Coast) being raided by waterpolice and being fined obscene amounts of money for having anchor light somewhere in the rigging, on the pushpit, cockpit roof etc.

Are you really telling us that Australia has opted out of the International Regulations for Preventing Collisions at Sea?

 

[simonfraser]

In the Colne river off Brightlingsea, several dark black boats near the centre with no lights at all
Ones that have a low light showing the cabin top / water are the most useful ones imo.
Mastheads just add to the stars, pointless for avoiding those boats.

 

[doug748]

My copper Davey lantern lasts all night

Yes, and you are probably ok with it, here is the Daily Mail with the lowdown:

http://www.dailymail.co.uk/sciencet...hanks-study-puts-distance-just-1-6-miles.html

....a fellow Davey lamp user.

 

[jiris]

Are you really telling us that Australia has opted out of the International Regulations for Preventing Collisions at Sea?

I am telling you what I've seen. Make any conclusion you want out of it.

 

[Kukri]

Thanks, forgot there was so much on their site when it was around.

And with the magic of the internet wayback machine - it still is

https://web.archive.org/web/20110827094623/http://www.bebi-electronics.com:80/specs.html
https://web.archive.org/web/20110319015643/http://www.bebi-electronics.com/


Interesting how much LEDs have come on, they used :

Off-Axis	Measurement
0˚	Minimum
	Average	14.0
	Typical	16.2
	Maximum	18.6

[TD="colspan: 4, align: center"] NSPW500DS -15˚ 1/2 θ[/TD]

[TD="align: center"] cd [/TD]
[TD="align: center"]lumens/
device [/TD]

[TD="align: right"]9.3[/TD]
[TD="align: right"]2.0[/TD]

[TD="align: right"]3.0[/TD]

[TD="align: right"] 3.5 [/TD]

[TD="align: right"]4.0[/TD]

The cree ones I used building a very similar light based on Bebi a couple years ago - typical 48CD at the same 20mA current (66% of max sustained current). Also the forward voltage seemed much better between LEDs, no real need to match them.

TYPICAL ELECTRICAL & OPTICAL CHARACTERISTICS (TA = 25°C)
Characteristics Symbol Condition Unit Minimum Typical MaximumForward Voltage
VF IF = 20 mA V 3.2 4.0
Reverse Current IR VR = 5 V μA 100
Luminous Intensity IV IF = 20 mA mcd 28200 48000
ChromaticityCoordinatesx IF = 20 mA 0.2895y IF = 20 mA 0.290550%
Power Angle 2θ½ IF = 20 mA deg 15

Michael is very much still around but not in Fiji and I have sent him a link in case he would like to chip in here.

 

[Kukri]

My copper Davey lantern lasts all night

So does mine. But to make assurance doubly sure if I am anywhere where there may be big stuff I Leave the all round white on as well.