LED deck or spreader lights

[Wckoek]

Originally Posted by sailcrazy

Our floods are each aimed down the respective side walkway (from the transom past the cockpit side, and then forward). When we hit the "intruder" switch, the foredeck lights the foredeck, the Spreaders light the mast area, and the 2 floods light each side.....the only unlit deck area (not directly lit) is the very center of the transom. Intruders have no place to go but overboard or back to their boat! Works much better than tacks spread every night! As I mentioned, they can all be used individually, as needed....or can all be turned on together with a single switch, depending on what we need to light up.

I do like the idea of their coverage, but wondered if it is overkill for my 36 foot, and if spreader done the job enough.
Do you have pictures of your boat and the lights in action so I can make a comparison?

[noelex 77]

Originally Posted by a64pilot

Geez, Nolex I like you but your incorrect.
The AH-64a was a pure analog instrument airplane, we wore “lip lights” on our microphones and had zero cockpit illumination,

It does not matter if the display is digital or analogue there is a great deal of information that is displayed and it is impossible to process lots of information quickly and retain the deepest levels of night vision. This is not dependent on the cockpit illumination but the displays themselves.

Originally Posted by a64pilot

Ever looked through a NVG? Night vision goggles? They display in green, not red, ever wonder why?

The photopic visual system is most sensitive to green. If you want to intensify an image with the least gain green is best choice, which is why it used. So the design of night vision goggles is engineered to produce the brightest image possible. Red would be a terrible choice.

These are all sensible descisions based on how the physiology of the visual system operates. To conclude that because night vision goggles present a green image then green must be be the best choice for preserving night vision is understandable but it is wrong.

Green is chosen for night vision goggles because it is the wavelength where the photopic visual system is most sensitive, red preserves night vision because it wavelength where the scotopic visual system is least sensitive.

[noelex 77]

Sailing at night is one of the very few remaining modern situations where preserving the deepest levels of dark adaptation can be important.

This does not mean that the maximum levels of dark adaption should always be the most important priority. The chartplotter, radar AIS etc all provide information and you cannot see all this information, process it quickly, and preserve the highest levels of dark adaptation. However, there are times, such as trying to spot crab pots, where the maximum dark adaption possible is invaluable, and this takes priority.

If you turn on a white light, even if it is a low intensity light, if it is bright enough to allow you see any detail (for example to read numbers) then your deepest levels of dark adaptation (not all dark adaptation) will be lost in that eye. It will take 15 mins plus before the maximum level of dark adaptation is regained. Using dull red illumination is the only mechanism where the photopic visual system (the system that has enough acuity to read numbers) can be used with minimal effect on the scotopic visual system.

This is not a myth, it is just the way the eye works.

[a64pilot]

Your right we are least sensitive to red, that is why it takes such a bright red light to be able to see anything by, and it takes a much less bright green light to see the same level of detail, so you need a much dimmer green light.
I know I’m not going to convince you.
If you really want to be as dark adapted as you can be, wear dark glasses during the day, and use no artificial illumination at night, none.
We called it Nighthawking, flying a helicopter nap of the earth with no Night Devices, and that is when we used either a lip light or a finger light or both.
Some liked the finger light, point at what you needed to see, and press the button with the side of your thumb to illuminate a dim, green LED.

However you did with zero artificial illumination.

Additionally there is a whole lot of training to see at night, off center viewing, how to scan etc. a whole lot. The night class was a couple of hours a night, five days a week for a couple of months.
Thirty years later I can still spend hours discussing the topics, cause I had to demonstrate knowledge of them yearly.

Here is a decent 10 level of you will study guide

http://www.usarmyaviation.com/Docume...HTSSTUDYGD.doc

[Bundyon]

I am going to try a pair of 6" barlights in LED off my spreaders. I think they will work very well. They have an IP67 rating & are used in the 4wd world, they are very robust & made in alloy and they are not expensive!

The discussion on night vision & what works is very interesting. I served 20 years on Oberon class diesel/electric submarines (Aust' Navy). Closed up in the Control room when dived on a Patrol on a dark night, night vision is critical, particularly for the OOW who is on the Periscope. No LED's back in those days, dimmable red lights everywhere. Three rows of heavy black out curtains on each side of the Control Room to stop the chances of any white light entering. I was operating the plot (Not electronic fancy stuff back then, but rather graph paper on a manual roll winder. Green print on the paper, red light and several colour marking pens, sometimes (lot's of times) the wrong colour marker was used!lol. I have seen the red lighting so dim, that you could clearly see the filament in the globe with barely enough voltage to make it glow.
Of course, if you were a stoker and lived aft of 77 bulkhead (Beyond the engine room) and it was your turn to go and pick up 3 or 4 meals at dinner time from the Galley,for the lads in the after mess, you had to make your way Fwd, through the Black out curtains each side of the Control room. Well you couldn't just barge blindly through the Control room, you had to wait till you got your night vision good enough to walk through the black hole. If you were lucky, one of the Control room watchkeepers would shine their red filtered torch on the deck so you get through. Coming back from the Galley with 3 or4 plates of Spaghetti Bog stacked on rings always made for an interesting trip. Always half your tucker left over the Control room floor! Standing waiting for permission & night vision to walk through meant that your food was going cold, then you had to battle through the engine room, especially if the two V16's were running whilst at Periscope depth. Nothing like a coating of diesel on your cold Spaghetti Bog!!
They were the days!!!

[StuM]

Originally Posted by Adelie

I’ve got a paper in this floating around on my computer somewhere. The recommendation of the paper agrees with what A64 indicates.

Specifically for chart reading use a dimmable white light set as low as usable. To use a red or other colored light you need greater intensity to be as usable and that ruins night vision longer.

For those who are interested, lots of discussion and links to relevant info:


http://www.cruisersforum.com/forums/...ion-67713.html

[boom23]

Fascinating information on cockpit light color! Thank you!

On a different note, I've always had underwater lights on my boats and I love them! For salt water, blue color carries further (I'm afraid to guess its effect on night vision...). With underwater lights you create your own aquarium at night as they attract fish. Several times, I've attracted huge schools of squid. An amazing sight and they taste great too!
I'm installing them on my next boat.

[noelex 77]

Originally Posted by a64pilot

Your right we are least sensitive to red, that is why it takes such a bright red light to be able to see anything by, and it takes a much less bright green light to see the same level of detail, so you need a much dimmer green light.

This is a common stumbling block that causes confusion. The eye is very insensitive to red light so even an intense red light is perceived as dull. The key is the effect on dark adaptation is not based on the absolute light intensity but the eyes response to that intensity.

An example to illustrate the point is IR or UV radiation. These wavelengths are only just outside visible light, but UV or IR radiation source cannot be seen by humans, so does not affect dark adaptation. An IR source can be seen by a suitable camera, but even if the source is intense it will not reduce the dark adaptation of a human.

The difference with red light is that are scotopic visual system does not have the same sensitivity to red light as our photopic visual system. Far red is not seen by our scotopic system but is seen by our photopic system. Therefore red light is usable by our photopic visual system but does not affect our scotopic dark adaptation.

Originally Posted by a64pilot

If you really want to be as dark adapted as you can be, wear dark glasses during the day, and use no artificial illumination at night, none.

Absolutely, very bright intense exposure to bright light does have a medium term effect on dark adaption and no light for 30 mins or more will give the best dark adaptation. However, there is balance between dark adaption and information from sources like instruments.

A military pilot flying a modern jet has a lot of vital information. The most efficient option is to sacrifice some dark adaptation to be able to process a large amount of information quickly. This is why red light is not the best option. This can also be true of sailing. If you want to frequently check your chartplotter, radar and AIS you cannot maintain great dark adaption, but often the value of the information outweighs the loss of dark adaption.

The other extreme is turn off everything and after 30 mins or so you will have the best dark adaptation but not know even basics like speed and depth.

A compromise is to maintain very good night vision but still have some information, this is where red light can help.

Originally Posted by a64pilot

http://www.usarmyaviation.com/Docume...HTSSTUDYGD.doc

That is quite a good basic guide, written from a aviation perspective but it still has some good tips. I notice it discusses red lens goggles .

[Zhyachts]

My new COOT 38 is all LED.



It has a 90 watt LED light on the pulpit, where it can not reflect on the boat, for crab-pot, debris, ice spotting. Unless there is fog or mist it does not seem to effect night vision. I noticed many commercial fishing boats have these.



And, on the stern, a 90 LED watt backup light. This is powerful enough to discourage unwanted boarders.

[StuM]

Originally Posted by noelex 77

If you want to frequently check your chartplotter, radar and AIS you cannot maintain great dark adaption, but often the value of the information outweighs the loss of dark adaption.
.

... unless you close one eye or wear an eye patch. Aaaaarhhhh!

[a64pilot]

Originally Posted by StuM

... unless you close one eye or wear an eye patch. Aaaaarhhhh!

That is one trick we were taught, close an eye when you fired a Hellfire, it’s motor made a very bright, very white light, and everybody had to watch their first one.
Actually if you flew the AH-64, you had one eye that was very well night adapted (the left one) and your right eye was not because you had a TV tube shining into it, your left eye you saw the real world with no symbology, your right eye was located about waist level and 10’ or so in front of you, so that if you looked to the right, your right eye was 10’ to the left of your left eye, 3’ of so lower and saw in the near infra red.
You started out using your right eye, squinting your left, but as you gained experience your mind could switch back and forth depending on if you saw a light or were looking at the FLIR, wanted to look inside of the cockpit or outside with the FLIR. Joke was if you flew enough night System you would eventually become like a Chameleon with independent eyes. That was actually a little bit of a concern, and we got enormous headaches at times.
I can remember dropping my pencil one night and looking down on the floor to get it, but only seeing trees very close up, rushing by, scared me pretty good, I was expecting to see my feet and the floor, but for some reason shifted back to right eye viewing, and the TADS would look straight down where the PNVS would not.
You had to be careful when you got out of the aircraft, cause you were almost blind in the right eye, and would walk into things, everything had a reddish tint to it also for awhile.
Of course seeing only through one eye meant you had no depth perception, something a pilot at very low level needs, so we had to be taught depth perception and distance estimation techniques for monocular vision.

[AndyEss]

One of the better discussions on CF in a long time. Thanks Noelex77 and ah64 pilot.
Good info, good attitudes

[wannacat]

I have combo red or white interior LED's in both my boats and without question the red is far easier on my eyes at night. If I need detail on a chart I use a small pen light if required then turn it off and let my eyes readjust before moving around much. I totally agree with "noelex77 that red is the way to go at night! Even if green is a little better , try and find combo white/green LED's that are made for a variety of fixtures on a boat, very hard to find!!!

[sailcrazy]

Sorry Wckoek.....no pics in my library, and I can't go get any. The boat is up on the hard in Puerto Rico (for the hurricane season), and we're at our MN home.

[SailRedemption]

Originally Posted by grecko

I'm thinking of adding marine duallys from Rigid Industries.

That's what we use, two with the Diffused lens on our 1st set of spreaders almost halfway from the inside. They are mounted sideways, tilt is towards/away from mast, so the beam goes longitudinal with the deck. They light up EVERYTHING. We also have the Aqua signal combo LED deck/steam light. It works well for normal jobs, but if at the dock or anchor the Rigids are in use. Both of the lights are about 25 or so feet up from the deck.

I give them both 2 thumbs up.