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

[ausaviator]

Red light is used because it doesn’t reflect off the windows, or certainly at least not anywhere near as much as other aircraft.

It’s used in aircraft for this reason and also we had red light in our police cars for night-time paperwork so it doesn’t upset the drivers ability to see out the windows. I have red in my aircraft and blue but blue is terrible for reflecting off the windows. Red is of course hard to read maps with as stated earlier in the thread.

[HuzurPapa]

As an ex-submarine sailor that stood many control room watches at sea I can tell you that periscope depth operations at night were dependent on red lighting. The entire control room would “rig for red” during the evening hours even though submerged. This was to insure the best possible night vision in the case of an emergency operation. One of the most dangerous times for a submarine is when it is coming to periscope depth because of the opportunity for a collision with a surface vessel. Submarines are stealthy and rarely use active sonar which leaves them vulnerable when operating at shallow depths. With night adapted vision it is possible to see through the periscope well before it has broken the surface. Many times I have watched porpoise and whales in those last few seconds before breaching.

[Kudos]

I've installed red LED strips and I like it. I can go below see what I'm doing in the cabin and come back top side on a pitch black dark night with no moonlight and still be able to see fairly well. I've had a lot of people tell me red is the wrong color and why. Honestly I don't care it works for me and it looks cool

[captqrunch]

Originally Posted by letsgetsailing3

So what's the answer, again?


Which color? Red or Green or Blue?

Red or green, but definitely not blue. Blue light can cause macular degeneration:

https://phys.org/news/2018-08-chemists-blue.html

[a64pilot]

There is nothing wrong with red light, the only issue is many think it’s OK to have bright red lighting, because red light is OK.
To start with “pure” red light is difficult to get, as is pure any color light, so there may be white in that red.
Your just better off with dim light period if you want to be night adapted, so if you choose red, make it dimmable.

[Jbingham]

Totally disagree. Red light offshore below deck is a huge help on tired eyes. I have a red/white light at the nav table and a red white light infringe of my electrical panel where I pull readings for battery voltage for log book. Also switching the instruments to red light mode is a huge help. No brainer. Plus with this set up if need white light just flick the switch to white light setting. My 2 cents

I’d gather that many who don’t see benefit don’t do long offshore (7 day plus) voyages. Tired eyes need all the help.

[Maka]

Interesting discussion. Learned some things.
That said, I'm not changing anything.
At night I have red lights below so people can see to get around.
At the helm I run my Radar with alarms on at night. It can see better than I ever could, especially through squalls, fog or any other weather.
The AIS is also on.
Consequently night vision is not as critical.
Cockpit is lit by plotter and compass, with the option of full white light.

If any work is required on deck at night, like reefing, I turn on the spreader lights and work in FULL white light. Safer IMHO.
Mostly I avoid night sailing when possible.

Submerged logs are impossible to avoid at night, even with the forward looking sonar.

[Georgiamarie]

I have been an aircraft pilot for 40 years. I have flown planes with all possible lighting schemes. For me, the Green backlit instruments are the easiest to view and on the eyes.

[JulienPete]

Originally Posted by Kelkara

This is an important issue when reading paper charts, the magenta ink all but disappears under red light ... and that magenta colour is used to mark lights, which is what you want to see at night.

Using a Blue Green light would likely make the chart go blank in the areas that are Blue Green? So maybe you would not see areas on a chart, like the areas that dry at chart datum.



It does seem that Blue/green light lets you see best https://www.quora.com/What-is-the-mo...or-in-the-dark However, is that a good light if you are looking paper charts?

[Jbingham]

In northeast we are constantly dealing with fishing boats that don’t use AIS and lots of lobster pots and fishing gear. Even with autopilot and radar got to constantly be checking around you...

[a64pilot]

The biggest reason that blue / green light has caught on so much is that it is the color that night vision intensifiers are least sensitive to, so it doesn’t blind goggles as easy as red or white, it does cause less eye strain though.
However the “secret” if you will night adaption is always use the dimmest light possible.
I know we all think night sailing takes great night vision, but it pales in comparison to flying low level at night where there are many things to hit, and people that do that are taught light discipline meaning use the least light possible to accomplish a task.
However of course balance that against safety, if you need to go on deck case something broke or whatever, turning on the spreader lights may be the thing to do and just lose your night adaption for 30 min or so.

However if you are planning on night sailing and want good night adaption, what you do during the day is also important, wear the darkest neutral grey sunglasses you can for starters, don’t drink or smoke. And try to get plenty of rest, it’s best if your Circadian rhythm has been reset to nights.
And eat well, Hypoglycemia has a strong effect on night vision.

[JCA320]

Originally Posted by tkeithlu

Want to demonstrate some of this? Wake up in the dark, stumble to the bathroom, turn on the light, but keep one eye tightly shut. Return to bed, turn off the light, and open both eyes. You will be able to see in the very dim light with the eye you kept shut, but will be blind in the eye you exposed to the bathroom light. Feels wierd the first time you do it.

Hence the pirate eye patch.

[Adelie]

Originally Posted by tkeithlu

....
Want to demonstrate some of this? Wake up in the dark, stumble to the bathroom, turn on the light, but keep one eye tightly shut. Return to bed, turn off the light, and open both eyes. You will be able to see in the very dim light with the eye you kept shut, but will be blind in the eye you exposed to the bathroom light. Feels wierd the first time you do it.

If I’ve gone back to bed in the dark either I’m going back to sleep and it doesn’t matter if I’m night blind or I’m there for other reasons and I’m happy to proceed by touch.

[Aethelwulffe]

1. Red light is not as visible at long distances. This is good, because your less intense leaked red light will not interfere with the "picture" of your nav lights, allowing other navigators to determine your angle-of-attack, meaning be able to see your relative direction of travel. One white light in the wrong place can and will confuse things, and they may think they are seeing your stern when in reality they are looking at your bow on a CBDR (Constant Bearing, Decreasing Range) collision course.
2. You see better with white light, at least small details, because *color* gives us a lot of information about objects. Red light, on the other hand, makes looking into shadowy spaces much easier, as your pupils stay open wider. If car headlights were red, we would have a much easier time seeing things on the side of the road (like pedestrians), and oncoming traffic would be blinded a LOT less.
3. Almost any single (narrow, "colored") bandwidth light is functionally better when you are working in an environment that does not have sufficient ambient light. At sea is certainly one.
4. If you restrict all light, excepting only a very few very dim red indicators (like a compass light turned waaaay down), you will find that you never really needed all that light in the first place. This is most true when you are actually out at sea, but still important when you are in a bay surrounded by light pollution.
5. Stood every watch in the US Navy. I can absolutely verify that watchstanders that come up the ladders reporting to their forward lookout watch straightaway after being on the Mess Decks grabbing their nasty MidRats tend to stumble blindly and must navigate by feel all the way. Furthermore, if you try to point out the obvious contacts (lights) on the horizon, they cannot see **** until they look through the "Big Eyes" binoculars. Folks rotating watch out of CIC (blue light) are better off, but still have issues. Quartermaster UI watches coming out of the often brightly lit red-light chartroom really don't have much of an issue at all, and within a couple of minutes, they are commenting on how bright the night is. "Boaters", with a face full of brightly lit chart-plotters and crap that use flashlights to walk the decks with are absolutely running freaking blind.

[noelex 77]

Originally Posted by Maka

If any work is required on deck at night, like reefing, I turn on the spreader lights and work in FULL white light. Safer IMHO.
Mostly I avoid night sailing when possible.

There are many situations on a boat where it is worth sacrificing some dark adaptation to perform a task better. Dull red light makes performing most tasks slower and more error prone.

It is helpful to think about managing your dark adaptation as a resource. It takes a long time to recover lost dark adaptation (as long as half an hour or more in some circumstances) so you need to anticipate future vision demands as much as possible.

For example, turning on the spreader lights rather than using dull red light will make reefing easier, but if a crewmember falls overboard it will be long time before you regain your best night vision. On the other hand, perhaps the good lighting provided by the white spreader lights will help reduce the chance of an accident in the first place.

There is no easy answer that fits all circumstances, but all offshore sailing boats should have the option of preserving the best night vision while still making available basic information. This can only be done by providing dull red illumination.

This does not mean that dull red illumination is always the best answer for all circumstances. There are times when sailing at night when it is worth sacrificing some night vision. Switching to white light to perform a task can sometimes be sensible, but be aware of the consequences and have the option of dull red illumination available for when it is needed.