Red light at night is a MYTH?!??!

[Auspicious]

Originally Posted by bradm85

Go a US Navy ship at night underway, ANY US Navy ship. You will see red lights and red lights only.

How long since you've been aboard?

[a64pilot]

Originally Posted by Aethelwulffe

Yes. You are flying instrument rules. 80's and 90's instruments had/have a lot of Hercules Monochrome "green screens", just like in the older CIC's on Naval Vessels. That is why you use blue. Different thing. Also, the blue light has certain "keep awake, stay calm-but-still-able-to-pump-adreneline" physiological quality that a single operator may find valuable.


https://www.aviationsafetymagazine.c...hting-choices/


Also, you find a lot of blue LED's pop up on stuff in the 90's because they were new, novel, looked cool at the air/boat show, and people were getting into the idea that instrument flying was the preference, not the fallback. You don't have flotsam and MOB's in aviation navigation, you have (generally) 100% coverage by VASI/PAPI also.

I’m going to go out on a limb and bet that he was not on instruments and the lights were blue / green.
At the beginning of NVG flying we would take critical instruments and fold down the hood that the lights were in, and snap a tiny chem stick and stick it in there and close the hood, this barely illuminated the instrument and avoided the red light and any unnecessary lights, later special instruments were made with large numbers on them and saw teeth pointing to which direction the needle needed go to get within limits.
Most crews loosened the round instruments and rotated them so that normal was needle straight up, that way all you needed to see was the needle and didn’t need to see any numbers on the gauge, right of straight up was high, left was low.
Best visual acuity when using your rods is I believe 20/200 and you cannot discern any color, only black and white, if you can see colors your using photoscopic vision, your cones, where you want to be using only Scotopic vision, that is your rods only.
Initial years were nuts with attempts of focusing one tube on the instrument panel and the other to infinity so you could at least see the instruments, later we learned to “cut away” the bottom of the goggle part that sat against your face and to see the panel you looked under the goggles. A lot of us could honestly listen to the engine and tell if we were close to overtorquing, you can hear the compressor change it’s note.
Latest aviation goggles mount to the helmet and you have no real easy to see around, such a simple obvious solution, but it took time to get there.

However the earliest days of military helicopter night flight were all “night hawking” that is flying at night completely unaided and no lights at all, just the mark I eye ball, think Vietnam era, there were a lot of helicopters flying at night and at altitudes where sailing concerns about flotsam and jetsam are a joke, hit a tree, towers, wires etc at 90 kts in a Huey and it’s all over, pretty much instantly. And they were kids, and like everything else your night vision is much, much better if your young.
Turn on a landing light or any light and you get shot, one very strong reason I avoided instrument lights is if that’s all they can see on the ground, they are aiming in your cockpit, and I’d rather avoid that.

I’m not old enough to have flown in Vietnam though.

Anyway there was an enormous amount learned in a pretty short time, then based largely on what was learned and to greatly reduce the vulnerability of a helicopter it was determined to focus mostly on night flight, all fighting was preferred to be done at night.
Millions and millions of dollars were spent on research and development, development of FLIR systems to fly at night etc.
So a huge amount of attention was spent on deciding on which types and colors of light were allowed and intensity, even food and vitamin supplements were studied, wearing dark goggles during the day etc.
How to change your Circadian rhythm so that your at your best at night.
You can ignore all of that research and data and continue to do as good ole grand dad did in WWII or how it’s done on submarines etc and justify anything you want to, but most of it’s published if you care to open your eyes and look.
People have been going to sea for a very long time and the old ways work, maybe not as well, but they do work.

[a64pilot]

Originally Posted by MVNightWatch

Make mine whatever the US Navy submarines are using. Can’t think of anyone who would know better.

Why? They almost never, ever use visual sight do they?

[a64pilot]

There is this from Passagemaker
https://www.passagemaker.com/technic...ntific-blunder
And apparently if I read the article correctly red light has been gone in subs for quite some time, apparently blue filters were first tired and they have apparently settled, on guess what?
Dim white light.
https://apps.dtic.mil/dtic/tr/fulltext/u2/a273682.pdf
Date of report was 1993, but it seems all the data and experimentation was from the 80’s, right about the time the Army was going though it’s night fighting evolution.

[Leaff]

Red light as used by the military is a red filter with a specific wavelength to preserve night vision for your eye once acquired. It is also a light that will not carry which helps to see but not be seen. In other words it lets you read a map centimetres away but is not seen by the enemy meters away and when you lookup to the night sky you can easily see shapes and movements under very little light. If you use a white light you’ll be almost blind for 15 to 20 minutes in the dark.

It think this was not explained properly as it has nothing to do with your application just the opposite. Navigation lights, some of which are used for vessel navigation are not the same red as the black out wavelength requirements of the military. Those are used in combat condition on equipment like vehicles to limit being seen but allowing enough vision to see the vehicle in front of you in convoys.

[mikeo16]

BMW cars and some of the other German cars have always used red lights to illuminate the dashboard instruments. I just assumed it was to eliminate night blindness

[Wotname]

Originally Posted by mikeo16

BMW cars and some of the other German cars have always used red lights to illuminate the dashboard instruments. I just assumed it was to eliminate night blindness

Do also consider they have enough white light in their headlights to destroy any night vision the dash lighting saved .

[Lihuedooley77]

Just want to inject here that the saying is actually RED SKY AT NIGHT, SAILOR DELIGHT, RED SKY IN MORNING SAILORS TAKE WARNING.

That nautical terminology had nothing to do with electronic wonders of any kind.

And I know that is hard to believe. But real seamanship and coastal piloting, and marine weather knowledge is history.

And now we see posts, that the electronic whiskey deltas cannot read their effortless
electronic read outs.

I am also a victim, if I wear my dark aviation prescription glasses to the market, I cannot see the read outs from the electronic display at the check out counter. It is just a black screen. I need my clear glasses. Not only that, but now with the check out people wearing masks, my ears cannot understand what the heck the checker is saying.

On the positive side, at nearly 80 on the 23rd of May, nothing to do with flying aircraft , or skippering sailing vessels, we hiked 5.3 miles in a wilderness area, and accumulated 14.500 steps according to Erica's her super I phone, seven plus. I can figure it out by time, and roughly knowing my, elapsed time. The old bones move at about 2 MPH. Both results are about the same. And I mean really close.

Life now is a wild guess for us. But we are still alert enough to get thru what ever. Before I retired from sailing, as a U.S.C.G Merchant Marine Capt, I had to use my light sensitive lenses glasses down below at the chart table.

the aviation prescription sun glasses I wore topside to protect my eyes. If I did not follow that procedure top side , the glare from the sun would actually cause me to see little black dots for many days . Not good.

Aye, and the positive ending to our hike today, was my reward of Jameson Irish Whiskey and my best beloved fixing a fantastic dinner. NO electronic devices required.

[a64pilot]

Originally Posted by mikeo16

BMW cars and some of the other German cars have always used red lights to illuminate the dashboard instruments. I just assumed it was to eliminate night blindness

It’s fashionable, looks cool the marketing dept likes it.
Nothing do with anything else.

[a64pilot]

Originally Posted by Leaff

Red light as used by the military is a red filter with a specific wavelength to preserve night vision for your eye once acquired. It is also a light that will not carry which helps to see but not be seen. In other words it lets you read a map centimetres away but is not seen by the enemy meters away and when you lookup to the night sky you can easily see shapes and movements under very little light. If you use a white light you’ll be almost blind for 15 to 20 minutes in the dark.

It think this was not explained properly as it has nothing to do with your application just the opposite. Navigation lights, some of which are used for vessel navigation are not the same red as the black out wavelength requirements of the military. Those are used in combat condition on equipment like vehicles to limit being seen but allowing enough vision to see the vehicle in front of you in convoys.

I don’t believe any branch of the US Military uses red light anymore, especially after finding that data I found on US Subs going to white light 20 years ago. Read that link, it quotes dozens if not more studies that led the US Navy to dim white light.
But also blackout drive lights in vehicles has always been dim, white light. I assume it still is, but I did retire almost 20 years ago.

[Training Wheels]

Originally Posted by Auspicious

For context, I am a naval architect and marine engineer. Most of my career was on US warships and some specialized civilian government platforms. The answer the specialists gave us for specifications in the 80s, 90s, and 00s was dimmable white. When I was in senior management part of my role was to push back. "Trust but verify" and science was pretty clear and consistent. SLEP was at least ten years behind new builds.







This is probably the most useful bit of perspective in this thread. If you can't get dressed without turning on lights when you get up for 12-4 you have an organization problem, not a light problem. If you can't use the head without extra light, you have a memory or orientation problem not a light problem.







Bright is bad.



On modern boats there is plenty of ambient light below. Indicator lights on electrical panels, USB chargers, VHF handheld chargers, various other devices provide plenty of light to move around IF YOU DON'T USE SUPPLEMENTAL LIGHT.



Light discipline is something I emphasize in daily email to crew heading into a delivery. For most people it doesn't completely take. Folks don't realize how much they don't see.



I have a real peeve about headlamps. Just too many times crew come wake me up with a red headlamp on aimed right at my face. If they manage not to make that mistake when I come up the companionway they turn at the noise and *bam* my night vision is shot. I warn crews: one strike and you're out. I take the headlamp until we hit the dock. No second chances. There are times when a headlamp makes sense (fixing something on the engine) but general watch duty is not one.



There is discussion here about things like compasses and instruments. On modern boats just about everything can be covered at night. Databar on the chartplotter can be configured for everything you need and ancillary displays covered completely. What are you using the magnetic "steering" compass for when HDG and COG are on the plotter and the autopilot is steering? Turn off the light or cover it. Covers lost? Tape aluminum foil over the instruments. Yes they are convenient and a benefit and sure use them during the day but the light is not worth it at night.



I concur with the advice to use the tricolor at night whenever you legally can. Note that on most boats the stern sector lights up the wind indicator nicely.



While I'm taking potshots I'll take one at catamaran designers who clearly don't understand passagemaking. In winter, when the sun sets early, there is not way to provide task lighting in the galley for dinner prep and wash-up. Turn on lights and on all but a very small number of designs the watch can't see. How is the watchstander to use the head? Simply bad design. Some operational expedients help (mise en place, cooking ahead for warming, clean up after dawn) but they are poor and come with their own issues. A pox on their houses.

Great post!

[Leaff]

Originally Posted by mikeo16

BMW cars and some of the other German cars have always used red lights to illuminate the dashboard instruments. I just assumed it was to eliminate night blindness

Yes it is. That was the point of my post. Some cars used an orange red light.

[Auspicious]

Originally Posted by Training Wheels

Great post!

Thank you. Nice of you to say.

[ob44]

The US. Navy has used red light on the bridge for forever. Merchant ships use red light on the bridge at night and have done so for many decades. It works. I don’t know why you would even question it.

[phild23]

No myth at all, astronomers the world over use red light when observing to preserve their night vision.