Nighttime nav. light

[josko]

What do people use for chart illumination during nighttime navigation? My BD headlamp does have a low-power red mode, but finding it typically involves cycling through several high-intensity/white light modes and resultant loss of night vision. I'm thinking about a tiny red pen-light, but haven't found just the right waterproof one yet. Any favorites out there?

[Inverseyourself]

Mildly off topic, FWIW, a high-ranking East Coast coach stated during a BCU course last November that the whole red light saves your night vision thing is a myth. Not sure why they would use red light on the bridge in Navy surface vessels as well as submarines, at least in the movies. I (kind of) still believe in the myth, I have to admit.

Edited October 13, 2015 by Inverseyourself

[josko]

Mildly off topic, FWIW, a high-ranking East Coast coach stated during a BCU course last November that the whole red light saves your night vision thing is a myth. Not sure why they would use red light on the bridge in Navy surface vessels as well as submarines, at least in the movies. I (kind of) still believe in the myth, I have to admit.

Try it.

[PeterB]

a glow stick tethered to a short line on the pfd works well. when needed you can deploy it it to read your chart, then to tuck in or hang wherever on your person in the mean time.

[EEL]

I suppose reasonable minds can differ about the value of using a red light and a quick search on Google will provide lots of fodder for the debate. Once upon a time when preserving night vision and having a means of illuminating maps at night was a matter of some importance as in you wanted to see and not be seen, the use of a very dim, indirect red light seemed to work well. Since dimness is critical, I second Peter's suggestion of using a glow stick and personally would select a red one for the task. There are small red LEd flashlights using AAAA batteries which I have carried, but they are not waterproof.

Ed Lawson

[leong]

Once upon a time when preserving night vision and having a means of illuminating maps at night was a matter of some importance as in you wanted to see and not be seen, the use of a very dim, indirect red light seemed to work well.

Why would you not want to be seen? Navy Seal?

Just wondering.

Edited October 14, 2015 by leong

[josko]

I just want to see and not loose my night vision. Have any of you folks actually tried reading maps by lightstick at night? For me, the lack of shading defeats the purpose.

Edited October 14, 2015 by josko

[John Martinsen]

Don't many of the newer headlamps have a dimming mode, so you can turn the power down low? Seems the best option. Or keep the lamp cupped in your hand until you find the right setting so it doesn't mess up your night vision.

Having pretty good night vision, getting beamed by someone else's headlamp is quite aggravating, if in a group make sure to keep your head bowed.

Doing some nighttime navigation is on my to do list.

[Phil Allen]

Science geek cap on: The rod cells in the eye are most sensitive to green light (500nm), with a significant fall off when the light becomes bluish or reddish. So for the eye and brain (which is really what does the seeing) dim red light is substantially dimmer than dim green light. i.e. humans are much less sensitive to detecting it. Which may be a good or a bad thing

I'd play with different colored lighting to look at charts, since chart features are designed to be read under white light and you may lose contrast of colored features with monochromatic lights.

And the pirates eye patch trick works if you have to try and maintain dark adaption while looking at something "bright". Close one eye and keep it closed while looking at bright lights. The closed eye won't have changed it's sensitivity (as proven by "myth busters".

best

Phil

[cgr]

Josko,

This headlamp switches to red easily and is waterproof.

http://www.amazon.com/Brightest-Headlamp-Flashlight-Running-Camping/dp/B00R1KSK8G

[cgr]

Josko,

This headlamp switches to red easily and is waterproof.

http://www.amazon.com/Brightest-Headlamp-Flashlight-Running-Camping/dp/B00R1KSK8GG

[Pintail]

Regarding "the myth" of red lighting (and BMW, I think, use it in their cars?), I can tell you that Cessna dropped red cockpit lighting about forty-five years ago and replaced it with white, rheostat-controlled lighting. That should be worth considering...

Who on earth reads maps (sorry: charts) at night? In fact, who goes anywhere at night? Shouldn't mortals be tucked up tight in their beds? If anything is needed, perhaps a small-size glow-stick underneath one of those detachable compasses that are held in place with bungees. Surely you only need your compass heading?

Oy, vey...

Edited October 15, 2015 by Pintail

[PeterB]

I've read charts at night by glow- stick with no problem, but others may not like it. It;s a good idea to also keep a tiny waterproof/dive light tethered to the pfd, to turn on and off for sort times when needed; looking at a chart in more detail , fussing with gear, etc.

[gyork]

Try this on for size Josko: http://www.homedepot.com/p/Life-Gear-4-in-1-LED-Glow-Stick-Flashlight-Red-LG115/203425268

Not waterproof to my knowledge, but I've modified mine to conveniently access from PFD. I cut off the redundant whistle end, then re-tethered the lanyard to the end through a newly-drilled hole:

Since one doesn't want/need the excess light staring back at you, a piece of duct tape, 1 inch-wide X length of the light barrel can cover 1/2 of the surface area of the glow stick. A piece of slightly smaller aluminum foil on the inside of the tape will help reflect light onto your chart or wherever.

Is it worth the trouble to add the duct tape? You decide by comparing illumination without and with the tape below:

The same set-up with a white light, http://www.homedepot.com/p/Life-Gear-Waterproof-LED-Glow-Stick-Flashlight-LG123/203426717

this one advertised as waterproof, works slick as a deck-mounted compass light, as seen here:

[prudenceb]

Just finished tagging along on a 5* training with John Carmody this wknd, which included a night nav exercise. FWIW, John said he is not a fan of using red lights (and indeed glow sticks!). Rob and Cathy, who were both there as well, can correct me if I'm misprepresenting what John said, but his point was that the temporary loss of any night vision that might ensue from using a white light to read a chart is far outweighed by the benfit one gets from actually being able to clearly see, and consult, that chart. One in our group, who was leading us for that leg and doing chart work with a red light, was unable to see shoals - with small breaking waves - marked on it, and we had to do a last minute maneuver to avoid them. Had she been able to better see the chart, we would have steered a wider berth and stayed well away from trouble. (As it was, it was a flat calm night - but completely overcast so no moonlight to help us - and when we got close we could hear, and then see rocks and waves, so it was a no harm/ no foul situation. Had conditions been sportier, knowing exactly what was ahead would have been much more important.)

pru

[EEL]

Regardless of the opinions about whether red light is useful, I believe intensity of light is quite important. Always use the lowest intensity that enables a person to see what they need to see. Using a bright light is going to wreck havoc on you night vision and it can take nearly an hour to recover.

Ed Lawson

[prudenceb]

Regardless of the opinions about whether red light is useful, I believe intensity of light is quite important. Always use the lowest intensity that enables a person to see what they need to see. Using a bright light is going to wreck havoc on you night vision and it can take nearly an hour to recover.

Ed Lawson

We found that using the regular old white light on a regular old headlamp, aimed down at the chart - and not into the eyes of your paddling companions ;-) - worked well and did NOT wreak havoc on night vision for more than a minute or so.

pru

[EEL]

Okay, I get the point. In a non critical activity and some ambient light anyway, you can just use a headlamp and not worry about the details. I tend to forget the importance of the frame of reference. I'll stand by my opinion/comments when it is important to maintain a high level of night or scotopic vision.

BTW, here is a test for true night vision situations. Can you see an object in your direct line of sight or do you have to look at an angle to see it? Or, more interesting, can you see an stationary object when you are stationary without moving your eyes or head?

Ed Lawson

[Marshall]

Princeton Tec Point light clipped to the band of my Petzl Vario Rush (wicked bright) or on the brim of my cap has worked well on the night time paddling portions of Watertribe events.

6 or 12 lumen mode. Been water resistant enough to get bashed with waves and keep working. About $14

See you on the water,

Marshall

The River Connection, Inc.

Hyde Park, NY

www.the-river-connection.com

[PeterB]

Regardless of the opinions about whether red light is useful, I believe intensity of light is quite important. Always use the lowest intensity that enables a person to see what they need to see. Using a bright light is going to wreck havoc on you night vision and it can take nearly an hour to recover.

Ed Lawson

I agree: a very dim white light is all one needs to look at a chart: low enough intensity oughtn't mess with your night vision if left on for the short time it takes to consult the chart , and brighter is not a good thing. The light can reflect off the glossy laminated surface of carts or chart cases, and make the chart hard to read. Lights seem to be getting brighter: I think maybe the new LED technology makes it easier to make a smaller brighter light, finding a small, handy and low intensity waterproof light is not so easy.

[rfolster]

I will agree with Pru that, during the 5* night navigation, i was using the red lights on my headlamp and having a really difficult time seeing the chart. At one point, John and I were discussing the color of a particular navigation aid, and it's lack of notation on the cart. When he came over to see my chart, he told me to stop using the red light and put on the white. It made all the difference in the world to be able to see such things as the difference between the blue water, the green tidal zone, and the yellow land, as well as seeing small details and text on the cart. I as well did not suffer any serious loss of night vision, and if I did, it was just for a brief second. John did say that he is more than willing to give up a moment of night vision to get a better look at the chart, and I completely agree. I will concede that, if you were to spend half an hour looking at a chart at night with a bright white light, your night vision afterwards would be severely hindered for an extended period of time. However, when using it for maybe ten seconds to verify your location, heading, or route, the vision loss afterwards is so brief that it is inconsequential.

Getting back to the issue that Josko first offered, I as well found that my particular headlamp uses the same on/off button to toggle between the red light option, as well as a high-intensity single-lamp setting and a lower-intensity double-lamp setup, each being able to be dimmed only after coming on at full brightness and holding the button to dim it. The on/off button is held down to toggle back and forth between red and white, as well as a brief press to switch between the two intensity settings, with each press first switching one on, then off, then switching the other on, then off, going back and forth between the two settings. This does make it impossible to select a lower intensity of white light each time. I am now also looking for a second light source that is probably not a head lamp, but a fixed white light that can be attached to the PFD so that it only points down towards the chart, and has a permanently lower light intensity or able to be fixed to a lower setting. I would then save the brighter headlamp to only be used during emergencies such as an approaching vessel.

One final notes about saving night vision. During the night navigation, we all put glow sticks on our boats, PFDs, or both. We all used either red or green to avoid the harshness of a white light (going back to the long-term exposure issue). We found that one green glow stick was extremely bright and distracting, while another red one was almost not visible, yet but there is no indication on the packaging to indicate the intensity of each glow stick. It was later discussed that, if none of us had used any glow sticks, we might have preserved even more of our night vision, and would have been able to see each other just fine. Definitely something to think about, experiment with, and most importantly, consider only on a case-by-case basis.

[Phil Allen]

getting away from Josko's question about chart reading, but I like the phosphorescent plastic glow sticks from UVpaqlite that Steve Maynard introduced me to on a 5* training. Leave them out for a while in the sun or charge them with a flashlight and they glow dimly for a few hours. No where near as bright as the chemical glow sticks but sufficient to find people or boats in the dark.

best

Phil

[josko]

A few comments from my nighttime nav. class last week: with red light (headlamp) I couldn't read my boat-mounted compass (too far), my hand-held compass (some idiot made the marks in red), or read my chart (too fine detail). All students started out with red lights, but ~hour into it, everyone was flicking on their low-power white lights to get anything done.

Big difference between a shipboard chart room and kayak deck.

[rick stoehrer]

old string but i just saw it....fwiw...

we found that if we could preserve our night vision we could see pretty well at night...if you preserve your night vision....so....we took very small lume sticks and stuck them UNDER a portable deck compass mounted with bungies....we taped them in there....you crack the little sticks (as many as you can jam under there) make a ball of tape and then tape that onto and under the bungie attached deck mounted compass...voila...a lit compass with no light reflected back off of glass of the compass distract you or trash your night vision. actually worked really well.

for reading charts, yeah a white light head lamp set to low is more than enough. make sure to keep the thing angled toward your immediate foredeck...you don't want to trash someones night vision....and they'll let you know if you do. loudly.

at night we set up very specific roles....too easy to lose track at night....so YOU will navigate, YOU other person will be the last man and no one gets behind you, YOU other person will keep the group together....that way the navigator can concentrate on just navigating....everyone sings out their number in the group repeatedly...so if there are 6 people ANYONE can sing out their number and then you go through the cycle til everyone is accounted for....so member number 5 shouts 5, and then # 6 shouts 6, #1 shouts 1....so on and so on until everyone has piped up.

before you launch you may wanna talk about your "plan" if you get separated...whistles, waiting...safety bearings and radio frequencies....some things to think about.

float plan? you got someone waiting/knows you're out? they expecting a call? how long you wanna wait in an emergency for the cavalry?

attach glow sticks to the bow (the end the rescuer mostly wants in a rescue) or both ends of the kayak and attach a glow stick on a line to your pfd....that way if your out of the boat, you can swing the glow stick around and the group can find you (light and movement) and your boat has glow sticks on attached so that can be found too.....you of course, have a strobe for emergency....and a radio.

what else?

merry christmas to all.