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Old 10-09-2018, 10:36 PM   #21
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I do. "No mariner shall rely on one single source of navigation". Plenty of stories here of chart plotters getting people into trouble.



A little LOW LEVEL white light is ok. You recover quickly. In fact, I find all those plotters and other screens a lot more interfering with my situational awareness at night than when we didn't have ANY of that. I've been known to put towels over them except for the occasional peek.


The key being low level as you highlighted. I have Raymarine MFDs. At night I turn down the brightness to as low as it will go, 10%.

I also agree with Oscar on printed charts. This summer I had a short time where my plotters crapped out. I was in unfamiliar waters with hidden rocks, no plotter and no GPS. I was very happy to have paper charts and a compass at hand.
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Old 10-09-2018, 10:42 PM   #22
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I was very happy to have paper charts and a compass at hand.
Take some bearings and get a fix, like the ol' days?
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Old 10-09-2018, 10:59 PM   #23
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I do. "No mariner shall rely on one single source of navigation". Plenty of stories here of chart plotters getting people into trouble.
Almost no one uses printed charts as their primary source of navigation in 2018. Yes I have them onboard, and actually prefer a hand drawn chart to an electronic vector chart. However I routinely use only computer screen rendered versions and almost never look at an actual piece of paper. I think nearly everyone does the same. Hence my question "who uses paper charts?"

A NOAA or CHS raster chart rendered on a computer monitor is perfectly readable, including the magenta lines, under red light or in total darkness. Again, these displays do not depend on incident light, they create there own. The ambient light makes no difference unless there is too much of it (bright sunlight).
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Old 10-10-2018, 01:00 AM   #24
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Take some bearings and get a fix, like the ol' days?

Yup. Like I learned as a kid.
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Old 10-10-2018, 01:17 AM   #25
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Have a builder-installed map light. It contains several white bulbs with the option of a single red. Since I haven't sailed/boated at night with any interior lights, I've no further comment.
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Old 10-10-2018, 02:34 AM   #26
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A little history... In 1965 the destroyer Frank Knox ran aground on Pratas Reef. The story I heard in the navy, the Knox was running at night and someone plotted a course across the reef, not seeing the red markings in the red night lights. Red and magenta marks and lines on the charts of the time don't show in red lights. It took 35 days and several tugs and salvage ships to get the Knox off the reef. They used expanding foam to force out the water and seal the hull. The machinery spaces were flooded. Musta been a job to get the foam out. The ship served 6 more years, was sold or given to Greece and served another 20 years.
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Old 10-10-2018, 06:34 AM   #27
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The US Navy submarine force stopped "rigging for red" in the control room before coming up to periscope depth at night about 30 years ago. Shifted to low level lighting in 88 or 89.

The OOD would wear red glasses in the control room prior to rigging for red to adjust his eyes even more.
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Old 10-10-2018, 07:15 AM   #28
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Hi,


The article found the same thing that had been known for decades, because of the red light due to wave frequency, color separation is not the best possible, This is taught here for children at school.


There is nothing to change how the human eye's wrists allow a night vision and other than the red frequencies in the light give impulse and you lose at least a part of the twilight of your sight.


Nautical charts are at least here, therefore, in addition to color, the symbols of the Direction of cardinal signs and lateral references, so there is no need to distinguish them with colors. There is really nothing new in this article or a scientific reference to a new research result on the subject. Red sing only electric line, pipe line etc.



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Old 10-10-2018, 10:20 AM   #29
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So my question would be, if we knew about the issues with not being able to see red markings on charts several decades ago, why haven't they changed the standard coloration for charts so that it does not include red? Wouldn't that be the easy/cheap way to solve this whole issues!?!
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Old 10-10-2018, 10:27 AM   #30
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All of my interior red lights are on dimmers.
I use them primarily for making the steps known.
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Old 10-10-2018, 10:49 AM   #31
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Quote:
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Hi,


The article found the same thing that had been known for decades, because of the red light due to wave frequency, color separation is not the best possible, This is taught here for children at school.


There is nothing to change how the human eye's wrists allow a night vision and other than the red frequencies in the light give impulse and you lose at least a part of the twilight of your sight.


Nautical charts are at least here, therefore, in addition to color, the symbols of the Direction of cardinal signs and lateral references, so there is no need to distinguish them with colors. There is really nothing new in this article or a scientific reference to a new research result on the subject. Red sing only electric line, pipe line etc.



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Maybe nothing new, seems to me most posters disagree with the conclusions though and favor red light at night.
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Old 10-10-2018, 12:42 PM   #32
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Almost no one uses printed charts as their primary source of navigation in 2018. Yes I have them onboard, and actually prefer a hand drawn chart to an electronic vector chart. However I routinely use only computer screen rendered versions and almost never look at an actual piece of paper. I think nearly everyone does the same. Hence my question "who uses paper charts?"
I use papercharts to do initial navigation planning and course plotting. I create all my plotted courses in the Nav Display from there. I use the GPS/Display as my primary navigation tool.

I keep a chartbook beside the helm when I'm operating. Often when I zoom out, I loose detail, like some markers. I like to use the chart to get 'big picture' views and for verifying my upcoming markers and turns.
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Old 10-10-2018, 12:59 PM   #33
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A failing (historically) of electronic plotters is they use vector generated charts, with computer algorithms to declutter when zoomed out. The computer is not very good at determining which things are important to keep. Human cartographers are (or should be). For years with Raymarine MDFs, I kept a laptop handy because it could display the NOAA printed charts on screen. Prior to that I kept the printed charts handy.

The newest chart plotters from Raymarine (and I assume others) will as easily display the raster charts as vector, in fact they can be displayed side-by-side for comparison. Now I rarely refer to a printed chart. I primarily use the raster NOAA and CHS charts displayed on the plotter in preference to the Navionics vector charts though it is easy to switch back and forth and I frequently do. The raster charts have detail appropriate to that zoom level, as determined by the cartographer, so even a small rock will be depicted on a large area chart, if it is an important hazard to navigation. This is what vector charts still do poorly.

The big advantage to rendering the NOAA charts on screen is that they can be seamlessly stitched together, even when different scales overlap. You are never caught between two charts or two scales. This is a big improvement over paper. The disadvantage is the size of the display cannot compete with a 44 x 22" chart - if you have the room to lay it out - and the adjacent ones.....
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Old 10-10-2018, 01:39 PM   #34
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I think the controversy here is due to the author of the article drawing a faulty conclusion from the data. Red light DOES protect your night vision, but make it hard to see red ink on a paper chart, so the author says red ligting is not good for navigation. That does not mean that red light is not better for preserving night vision, which is what the author seems to conclude.
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Old 10-10-2018, 03:39 PM   #35
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I think the controversy here is due to the author of the article drawing a faulty conclusion from the data. Red light DOES protect your night vision, but make it hard to see red ink on a paper chart, so the author says red ligting is not good for navigation. That does not mean that red light is not better for preserving night vision, which is what the author seems to conclude.

Dim red light will allow for quicker recovery of night vision adaption than dim white. The difference isnít huge however. Dim white is much better than bright red as well. I agree that the author is missing the subtlety.

Also, keep in mind that if you have red light and you see a green, blue and red line on a white background, the red will look red, the green and blue line will look black, and the white background will look red. If the color of the red line is the same wavelength as the red light, AND is as reflective as the white background, it will blend in. So, you can see red ink just fine with a red light. The problem comes in discriminating it from the red appearing background.
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Old 10-10-2018, 05:09 PM   #36
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Almost no one uses printed charts as their primary source of navigation in 2018. Yes I have them onboard, and actually prefer a hand drawn chart to an electronic vector chart. However I routinely use only computer screen rendered versions and almost never look at an actual piece of paper. I think nearly everyone does the same. Hence my question "who uses paper charts?"

A NOAA or CHS raster chart rendered on a computer monitor is perfectly readable, including the magenta lines, under red light or in total darkness. Again, these displays do not depend on incident light, they create there own. The ambient light makes no difference unless there is too much of it (bright sunlight).
You got me there. I do often use raster charts on an electronic medium unless it's my home turf and I spring for a chart book.
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Old 10-10-2018, 06:20 PM   #37
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Originally Posted by Northern Spy View Post
The US Navy submarine force stopped "rigging for red" in the control room before coming up to periscope depth at night about 30 years ago. Shifted to low level lighting in 88 or 89.

The OOD would wear red glasses in the control room prior to rigging for red to adjust his eyes even more.
Maybe those were rose colored glasses. In my day we just called them the OD.
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Old 10-10-2018, 06:46 PM   #38
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Red/white LED's on dimmers in the Salon, Wheelhouse, and cabins. We are Dog Zebra at night when underway, but when needed to move around they work very well.
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Old 10-10-2018, 08:07 PM   #39
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Hmmmmm, I turn on my red light, looked at the magenta in my map book and it was still visible but, in gray.
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Old 10-10-2018, 08:30 PM   #40
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Hmmmmm, I turn on my red light, looked at the magenta in my map book and it was still visible but, in gray.

Yup. It is all about wavelength and reflectivity. Usually our ďredĒ lights arenít a single wavelength. The same with the colored lines. In your experiment, Iíd be interested to know what color the background appeared?
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