Viewing angle of Tri-Colour from dead ahead.

series_34_n_1_tri-colour-anchor_w.jpg

I fitted an Aqua Signal series 34, Red, Green and White LEDs are fitted into recesses in the moulding, so that there is a big lump of plastic between them.
When I powered them up and looked at them at home the cut-off seemed quite sharp. Further, they are designed as LED units, so I guess Aqua Signal have done their best to make them compliant.
I think they are a significant improvement on retro fitting tri-colour LED lamps to series 40 lenses, whether they pass muster on collision regs I don't know.
And as stated elsewhere in this thread, the boat is most likely to be yawing around by more than the overlap in colours on the series 34.
 
>COLREGS do not require tricolour. It MAY be used instead of side and stern light for vessels under 20m (Rule 25a i & ii )

Indeed that is true but the OP was talking about a bicolour and tricolour not side and stern lights hence I didn't mention them, it wasn't relevant.
 
blackbeard said:
Also incidentally; does anyone know what the cut-off angles for a purpose built tricolour LED (ie no lens) are? I must admit I can't see how it might be compatible with COLREGS but I am prepared to be convinced if someone can show actual measurements/illustrations to the contrary. Failing which, I will stick with a filament bulb.
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I have no idea what the actual cut-off angles are, but given that at least some brands are certified by official authorities I trust that they are within specs.
I can see nothing wrong with a filament light apart from the power consumption.
 
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>Each colour shows for 120 degrees...
>>No, they do not.


As I said the OP wasn't talking about deck lights or a steaming light he was talking about a biclour and tricolour at the top of the mast. A tricolour has three sectors of 120 degrees to make and all round light of 360. Side lights are not relevant to the thread.
 
KellysEye said:
>Each colour shows for 120 degrees...
>>No, they do not.


As I said the OP wasn't talking about deck lights or a steaming light he was talking about a biclour and tricolour at the top of the mast. A tricolour has three sectors of 120 degrees to make and all round light of 360. Side lights are not relevant to the thread.
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A tri-colour with 120 degree sectors would not meet the COLREGS.

The OP didn't mention the top of the mast although we may infer that for tri-colour and the bow for bi-colour.

The visible angles (sectors) for port, starboard and stern specified by the COLREGs do not change for bi-colour, tri-colour or individual lights. None of those angles is 120 degrees.

The angles shown in Nigel's diagram are correct regardless of light type. 112.5 + 112.5 + 135 = 360.
 
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Obviously we should all be using lights which are perfectly in line with the COLREGs. However, if one was to use an LED replacement bulb which gave a wider changeover angle between red and green, that wouldn't actually make you less safe, would it? A boat approaching you from nearly head on would need to move further to the side to get a clear green, wouldn't it? Which would actually be no bad thing...
 
YachtAllegro said:
Obviously we should all be using lights which are perfectly in line with the COLREGs. However, if one was to use an LED replacement bulb which gave a wider changeover angle between red and green, that wouldn't actually make you less safe, would it? A boat approaching you from nearly head on would need to move further to the side to get a clear green, wouldn't it? Which would actually be no bad thing...
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When you are far enough from the light for it to appear as a single point, how does it look?
R+G=Yellow.
Ideal for getting lost in background.
If the observer does not have perfect focus, or is looking through a rain spattered window how does it look?

As I said before, you also need to look at the green/white boundary.
 
YachtAllegro said:
Obviously we should all be using lights which are perfectly in line with the COLREGs. However, if one was to use an LED replacement bulb which gave a wider changeover angle between red and green, that wouldn't actually make you less safe, would it? A boat approaching you from nearly head on would need to move further to the side to get a clear green, wouldn't it? Which would actually be no bad thing...
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What about a boat that is crossing ahead of you. They see they are dead ahead and try to cross but it looks like you are following them around... Ideal to confuse them, and confusion in a crossing situation is not a good option!
 
blackbeard said:
Thanks for this, Ian, seems to be worth any amount of theory.
On whether the combination of LED and lens is consistent with COLREGS, the answer AFAICS is a resounding and definite NO.

Incidentally. I suspect that some combination of red and green seen together might possibly give a sort of mucky white. Which might not give the impression we are trying to convey.
Also incidentally; does anyone know what the cut-off angles for a purpose built tricolour LED (ie no lens) are? I must admit I can't see how it might be compatible with COLREGS but I am prepared to be convinced if someone can show actual measurements/illustrations to the contrary. Failing which, I will stick with a filament bulb.
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Obviously from the discussion so far LED replacement lamps do not comply with COLREGS when used in a bicolour or tricolour navigation lights; so I guess as far as LED lamp designers go, it's back to the drawing board.
 
I don't think I'm in a position to say that replacement LED lamps fitted to nav lights, designed for filament lamps, don't comply with COLREGS, I've not measured them accurately or at a realistic range (100's of meters). I just felt that, from my simple observations, I didn't want to take the risk.

Nav Lights designed specifically for use with LED lamps, like the Aqua Signal series 34 are, in my view totally different, I expect them to comply with COLREGS and I'm happy to use them and take advantage of the much lower power consumption. I don't see why a major player in this area would take the "reputation risk" of selling a non compliant product.
 
I have an aqua signal bi colour nav light on the bow of my boat and recently converted it from incandescent to worm white LED.

Looking at both from the bow each lens has width so from straight on you can see both red an green and as you move sideways you can still see the opposite lens eliminated until the lens is not directly in view. In my case this happens with both the incandescent and the LED due to the refraction of the light with in the lens. The main difference in my case is the fact that the LED is considerable brighter than the

Looking at the Geometry and because the lens of the nav light does have width the angle of view will depend on the distance the nav light is viewed from.

In my case standing close in front of my boat the angle at which the opposite lens disappears is greater than when the nav light viewed a greater distance from my boat.

My point if that even with a single vertical filament of an incandescent bulb there will be some of the light refracting into the lens away from the centre point.

In my non scientific tests the extent of the difference could b due to the greater brightness of the LED bulb.
 
Rogershaw said:
I have an aqua signal bi colour nav light on the bow of my boat and recently converted it from incandescent to worm white LED.

Looking at both from the bow each lens has width so from straight on you can see both red an green and as you move sideways you can still see the opposite lens eliminated until the lens is not directly in view. In my case this happens with both the incandescent and the LED due to the refraction of the light with in the lens. The main difference in my case is the fact that the LED is considerable brighter than the


Looking at the Geometry and because the lens of the nav light does have width the angle of view will depend on the distance the nav light is viewed from.

In my case standing close in front of my boat the angle at which the opposite lens disappears is greater than when the nav light viewed a greater distance from my boat.

My point if that even with a single vertical filament of an incandescent bulb there will be some of the light refracting into the lens away from the centre point.

In my non scientific tests the extent of the difference could b due to the greater brightness of the LED bulb.
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I too can see both colours when close up to the fixture on my bench, when I manoeuvre my viewpoint left or right it's the same when either an incandescent or LED lamp is used in the fixture. I can see both red and green up to, I guess, about 15 degrees either side of dead ahead. With a LED lamp installed the viewing angle may seem a little wider. In my case the LED lamp used had two vertical arrays in each sector making both red and green lights very bright, even a narrow view of the smaller area of filter seems very bright.

From my own practical observations, as you move further away from a dead ahead view of a tri or bi-colour, the distinct colours become very difficult to determine, both colours tend to blend together. With lots of boat movement, when sailing, viewing one of these lights from exactly dead ahead tends to be a transient experience rather than a view sustained for any length of time.
 
Oldhairy said:
The chap you spoke to had it right. I had expected a reply to your question before now.
COLREGS ANNEX I / 9(a) (i) In the forward direction............practical cut off between 1 degree and 3 degrees.........
(ii) ...........at 22.5 degrees abaft the beam.....decrease steadily to reach practical cut off at no more than 5 degrees outside the prescribed sectors
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I'm interested in what you think the implications are by having a wider cut off angle.
 
Adrian Jones said:
I'm interested in what you think the implications are by having a wider cut off angle.
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Nice of you to ask although my opinion is probably totally irrelevant. Like everybody else here I try to abide by the rules but I have no part of creating them.
Now the implications: When approaching another vessel from her quarter and trying to establish if I am crossing or overtaking. The smaller the cut off, the clearer the angle.
When crossing in front of another vessel I like like to know if she is standing on, altering to go behind me or altering to a converging course. A clear cut off is imperative.
 
Oldhairy said:
Nice of you to ask although my opinion is probably totally irrelevant. Like everybody else here I try to abide by the rules but I have no part of creating them.
Now the implications: When approaching another vessel from her quarter and trying to establish if I am crossing or overtaking. The smaller the cut off, the clearer the angle.
When crossing in front of another vessel I like like to know if she is standing on, altering to go behind me or altering to a converging course. A clear cut off is imperative.
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It's only from dead ahead that you just might be able to see the two colours of a bicolour. It's extremely unlikely at any significant distance you would be able to clearly distinguish both red and green. Seeing both colours from a mast top tri-colour given the boats constant movement, is even less likely unless it's dead calm, in which case nobody is going anywhere under sail.

I see no added risk by having a slightly wider cut off angle, if anything, it should result in approaching boats giving my boat a tad wider clearance.
 
YachtAllegro said:
Obviously we should all be using lights which are perfectly in line with the COLREGs. However, if one was to use an LED replacement bulb which gave a wider changeover angle between red and green, that wouldn't actually make you less safe, would it? A boat approaching you from nearly head on would need to move further to the side to get a clear green, wouldn't it? Which would actually be no bad thing...
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Spot on sir!
 
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