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Old 18-08-2013, 10:21   #286
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Re: Keeping Watch at Night ?

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Originally Posted by noelex 77 View Post
If you just sailing locally the above approach may be fine. When sailing longer distances there is a need to accomplish tasks at night that require good vision. Checking a map, paper or electronic filling in a log, even getting a cup of coffee all require some supplemental lighting.

The use of most flashlights for even a brief period will effect your dark adaptation for 1/2 hour. There are better ways of doing things and that is what this thread is all about.
In my experience, long distance passages require less frequent confirmations of one's position, whether on a chart or glance at an instrument. Coffee can be made in advance and kept hot in a thermos. As for the other activities, on a long passage log entries can be made less frequently. Checks against a chart? Unless close enough to known hazards to be of concern, why?

Near shore navigation is a different matter, and is when I'll have my g.p.s. in the cockpit with me. But even then, I'll either be on approach to a harbour with leading lights, lit channel markers - or hove to well off shore if not. Make my approach in daylight.
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Old 18-08-2013, 10:29   #287
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Re: Keeping Watch at Night ?

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I never use a flashlight at night. Unless for some very complicated rigging problem.

On the whole it sounds like you are a better sailor than me. Much better.

So sail on, Wrong.

Mark
Should we compare our tools too? Flashlights are useful on board for lots of reasons. Complicated rigging problems included. I use a flashlight to infrequently check my compass heading. Got a problem with that? Too simple?

No complicated analysis involved, so it must be a ho hum for many here at Cruisers Forum, eh?
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Old 18-08-2013, 12:00   #288
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Re: Keeping Watch at Night ?

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I use a flashlight to infrequently check my compass heading. Got a problem with that? Too simple?
No built-in compass light?

I am a bit of a light Nazi - no white lights at night.
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Old 18-08-2013, 12:11   #289
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Re: Keeping Watch at Night ?

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No built-in compass light?

I am a bit of a light Nazi - no white lights at night.
Yeah, a compass light that hasn't worked for 18 years. Just as well since it was so dim was of no use any way which is why I haven't bothered to fix it. The wind-up flashlight works just peachy.

Maybe there should be an in depth conversation about flashlights that produce different colours, scientific analysis and all. That should be fun! Great opportunity for some budding capitalist to make lenses, eh?
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Old 18-08-2013, 12:21   #290
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Re: Keeping Watch at Night ?

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Well IMO, based on multiple deliveries from US to the Bahamas and Caribbean, in my case the most important skill required for standing watch is knowing when to call the captain. One can't always choose experienced, well known, expert crew when making deliveries. It often comes down to going short-handed or going with green or unknown crew. I felt that having an extra hand on board so the captain got enough rest to make a clear headed decision was important.

I made three passages with at least one crew member that had never before been on a sailboat and several with crew members that had no offshore experience. It was my job to educate and evaluate each one and determine the level of responsibility they were capable of. Until I stood watch several times with each crew member under varying conditions, he/she did not stand watch alone. If we were in a demanding situation like crossing a major shipping channel, an area with reefs or other hazards, close to land, etc then I would either take the watch at critical times or be there to supervise the crew.

The worst "failure" I had in ten years of doing this was the one where a crew member fell asleep on watch. As mentioned in a previous post, this is something that potentially endangers the lives of the entire crew. At least a singlehander knows when he/she will be sleeping and makes some provisions for that, but when a crew falls asleep the captain doesn't know that the vessel is sailing blind and has made no allowances.

The reason I put that person off the boat was not because he fell asleep. It was because he refused to admit the seriousness of the situation. His response was, well nothing happened so no big deal and besides, we are way out in the ocean and what could happen anyway. Based on his attitude I could only assume that this could happen again so at the first stop he was sent home.




Which is more or less what I did, except in the beginning I talked a lot, explaining and instructing.




I think I did address this indirectly in my post. While I didn't set some exact distance that was considered a concern, no one was allowed to stand watch alone until I was certain they had a good grasp of how far off a ship was, day or night, and what was close enough to be a concern.

Regarding course changes, I also had a rule that anything more than a minor sheet trimming that could be done from the cockpit required at least two on deck.

I wasn't arguing with you. I was just expressing my opinion. Of course you would teach newbies and make sure more experienced people had the knowledge and skills *you* need.

But as skipper, I need my rest, and I would not want to be awakened by someone just because they saw a boat on the horizon. That's still some distance away. And personally, I have no problem with a knowledgeable person making a minor and temporary course change to avoid another boat, even if it were overkill. Better safe than sorry.

Since everything on my boat can be controlled from the cockpit, I would not require two on deck for what I'm talking about. I would require two on deck if someone was going forward, and frankly, there would be Hell to pay if that rule wasn't followed, no matter who the person on watch was. It could be Lin Pardee, but she's not to go forward without someone else in the cockpit, for several reasons.

If I were on someone else's boat I would of course abide by their rules, but I would include MY rule that I would not go forward without someone else in the cockpit. If that can't be done, I'll skip the trip.
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Old 18-08-2013, 12:25   #291
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Re: Keeping Watch at Night ?

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as for feeling weather change--is too late by the time you feel it, it is on you. you must also be able to see the weather. hear the subtle changes in winds...weather is a 5 sense thing. in some cases 6th sense is even better than all 5. in floriduh one also must be able to see the haze that precedes formation of thunderheads.

as for closed toed shoes--that is strictly irrelevant.
i sail barefoot so i can feel deck and control any sudden slipperiness easily. i tried sailing with shoes---fell too many times. keep that shoe thing on your own boat. i know many really super sailors dont wear shoes, so demanding closed toes on board is limiting your sailing partners severely and you WILL miss out on finding good sailors when demanding shoes.
so far , most all my crew i have found are shoeless souls.
my boat is a 24 hour a day sailing vessel. no stops in darkness fo r sleeping nor wtf. we go until we break. then we fix and go some more. there are many places to explore an d very little time in which to do that.

i give tests to potential crew--first i have them get something and bring it to me. if they figure out the correct item they may just work out. i am specific in my request for them, so it isnt like i am inventing a hoop for them to jump thru. is actually very simple and 2 out of 2 soul shave failed, so far.
i do not allow people on my boat until i know they are adequate and a positive influence in the adventure.
special needs souls need to provide for selves, a si am not able to do that, so i dont usually accept special needs folks. btdt to boats detriment.
i will accept no crew who has no appreciation of the needs required at sea.

knowing when to advise captain is important...something on horizon is not on a collision course with anything until it is on you. plotting a course of someone elses boat or ship isnt hard...wait until you see it and then decide where it is going. wake the sleeping watch too soon and that is not cool. off watch needs sleep . mebbe your ship on a collision course is a light out in gulf or an island you need to avoid.
wow what a flood of thread this time.....and by someone not practiced in the fine art of night and solo sailing. wow. impressive.

Zee is right about the preceding haze. It was pointed out to me once when I was around 23. I couldn't figure out why the skipper was turning around. He pointed it out, and i watched, and within 10 minutes there was this huge thunderstorm bearing down on us. That 10 minute lead meant that we got his little 21' boat back to the dock just in time.

I just watched it here, sitting by the pool. But I've also seen it in the midwest. One time while driving through OhioI pointed it out to my husband and he pooh-poohed it. 15 minutes later our older daughter said, "Boy that's really thick haze!" (it was pouring and hailing).
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Old 18-08-2013, 12:27   #292
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Re: Keeping Watch at Night ?

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How do you read at night without a light? I suppose a red headlamp might work.

My Kindle is backlit and the amount of light is markedly adjustable. One of the things I love about it.
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Old 18-08-2013, 12:28   #293
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Re: Keeping Watch at Night ?

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Agreed. Headlamps also free up both hands. I have stuck my small Maglite between my teeth, but that is not very effective.
The problem with head lamps is that it is a natural reaction is to look directly at another person when you speak to them or they to you. With a head lamp you just blinded them.

Certainly handy when trying to work on something by yourself and you need both hands but not allowed on my boat for general use.
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Old 18-08-2013, 12:44   #294
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Re: Keeping Watch at Night ?

Noelex,

The link posted earlier in this thread to an article for pilots on how vision works stated quite clearly that it takes 45 minutes to attain full dark adaptation. Therefore, it might be better for us to adopt that standard instead of the 1/2 hr. one. Our own perceptions may actually be deceptive to us, and we think it's better after 1/2 hr. than it really is. What do you think?

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Old 18-08-2013, 12:44   #295
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Re: Keeping Watch at Night ?

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Originally Posted by Wrong View Post
Yeah, a compass light that hasn't worked for 18 years. Just as well since it was so dim was of no use any way which is why I haven't bothered to fix it. The wind-up flashlight works just peachy.

One of those wind-up flashlights with the magnet in it?
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Old 18-08-2013, 12:46   #296
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Re: Keeping Watch at Night ?

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I wasn't arguing with you. I was just expressing my opinion.
I understand that and I was just responding. Didn't think it was an argument.

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But as skipper, I need my rest, and I would not want to be awakened by someone just because they saw a boat on the horizon.
That was exactly my point and why I did not hesitate to take untrained or inexperienced crew. I consider a well rested captain and crew a critical factor in good decision making. While I did emphasize repeatedly to every crew member that they should never, never hesitate to wake me if there was any concern at all, one that repeatedly got me up to see a far distant light on the horizon would receive some additional coaching.



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And personally, I have no problem with a knowledgeable person making a minor and temporary course change to avoid another boat, even if it were overkill. Better safe than sorry.
Same here. Only for major changes do I need to be called

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Since everything on my boat can be controlled from the cockpit, I would not require two on deck for what I'm talking about.
I prefer to run only sheets to the cockpit. Anything else like reefing lines, halyards, etc I don't like the additional complexity, lines running around the deck to trip over and the additional friction in the system caused by the extra blocks required.

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If I were on someone else's boat I would of course abide by their rules, but I would include MY rule that I would not go forward without someone else in the cockpit. If that can't be done, I'll skip the trip.
On this we are in complete agreement. I would of course add a few more deal breakers to the list as well.
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Old 18-08-2013, 12:50   #297
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Re: Keeping Watch at Night ?

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One of those wind-up flashlights with the magnet in it?
Yeah. But you'd have to get right up and intimate with the compass to cause any effect. I'm not that close with my compass, no soft parts...
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Old 18-08-2013, 12:52   #298
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Re: Keeping Watch at Night ?

"I prefer to run only sheets to the cockpit. Anything else like reefing lines, halyards, etc I don't like the additional complexity, lines running around the deck to trip over and the additional friction in the system caused by the extra blocks required.

Quote:
Originally Posted by Rakuflames
If I were on someone else's boat I would of course abide by their rules, but I would include MY rule that I would not go forward without someone else in the cockpit. If that can't be done, I'll skip the trip.

On this we are in complete agreement. I would of course add a few more deal breakers to the list as well. "


I would not call reefing a "minor decision." And, my boat cannot be reefed just from the cockpit. It is necessary at one point to go up to the mast, so there's the two person rule already.

But in addition, that's a MAJOR change, to reef (or sailing at night, reef more deeply) and the skipper/captain should be part of that decision -- in fact, the "decider."

Among other things, my boat is tricky to balance, and I would want to see for myself what the result of the new reefing was.

Another rule I would have is "everyone sits down to use the head, and no, the head is NOT located over the lifelines.
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Old 18-08-2013, 13:11   #299
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Re: Keeping Watch at Night ?

I couldn't find the post, but someone said they require anyone on watch to "stand", not sit down. On a side note, reminds me of many employers who won't let their employees sit, even when the job can be done sitting. Asinine.

Anyway, standing is no insurance someone on watch will perform the job effectively. I realize when there is more than one person on board, if fatigued to the point a person risks falling asleep standing, they can ask for relief.

Twice, on my approach to Trinidad where currents and unannounced squalls can be a hazard, I've stood, trying to keep awake. On both occasions I awoke multiple times just before my nose would have had a unhappy meeting with a very hard part of the boat.

Safer sitting on a rolling boat than standing anyway.,

I would not crew on your boat or any boat that made me stand while on watch.
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Old 18-08-2013, 13:42   #300
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Re: Keeping Watch at Night ?

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Originally Posted by noelex 77 View Post
When reading Internet sources you need to bear in mind that yachts at night have very unique requirements that are not matched by other night vision tasks that present in the modern world.

Modern pilots get most of their information from complex colour coded instrument displays. Military personal use night vision equipment (which is in -compatible with red). Drivers illuminate the road with powerful headlights.

The references have a lot of shortcomings, but if read them with to visual conditions present in a yacht and you will find that they are mostly supportive of red illumination for our conditions. (I must admit I gave up with the third reference I don't think they even understand the difference between rods and cones
Here are a few quotes:

The key then is finding a hue that we can have at a high enough intensity that we can see the detail we need without activating our rods to the point were they obscure that detail. Most source say this should be nothing shorter than 650nm. Experimentation shows a L.E.D. with a peek around 700nm seems to work best (perceived as a deep red). Note that red may be fatiguing to the eyes.


Thus, although there is no question that maximum scotopic sensitivity can be shown to be better after adaptation to red than to
white light, and that this advantage increases as the adaptation level increases, these results show that after adaptation to low inteniity levels observers do not suffer losses of visibility when tested under conditions which are above threshold and with targets which have sorne appreciable spatial extent.

If you must see detail (reading a star chart, or instrument settings) and can lose peripheral vision (see note 1), then a very long wavelength red at a very low level. Red really only has an advantage at very low levels (were the night blind spot is very obvious).


If you have any doubts look at this graph. If you want to turn on a light and avoid bleaching out your scotopic vision (shown in blue) do you turn on a light of wavelength 650nm + (red) where your scotopic sensitivity is close to zero, or do you choose a light of shorter wavelength?
The second link was to a US Navy study that concluded that low intensity white light was superior to preserving night vision in submarines than red light at an equally useful intensity. They made recommendations to change their current lighting away from red.

The third link contained this:
"By the mid-60's, scientists had discovered that red-light saturation actually *decreased* night-vision, to some extent. It wasn't necessarily the hue of the light that affects night-vision (though that fact is still debated), but rather the intensity of illumination. See, red-hued light requires almost *twice* as much illumination to provide the same candle-power as lower-frequency (420-460 nm) blue-hued light. Thus, red-light is prone to induce more glare, and will negatively affect the cones (photo-receptors) of the eye. Blue-green light at a *lower* illumination is actually better, providing more color "information" per degree of illumination. "

I fully understand the graphs you present and their implications. I understand how the red light myth has plausibility at first glance. I am just pointing out that actual studies have shown this common perception to be wrong. In every case where controlled studies have been performed explicitly to determine if red is the best color for preserving night vision, the results were that the intensity of the light, not the color, is what is important in preserving night vision.

In practical terms, no light is needed at all until a task requiring visibility is needed. At that time, the lowest intensity light of any color that allows that task to be completed as concisely as possible is the best choice.

Red almost never fulfills that criteria.

The "night" mode on the B&G Tritons uses a completely different color pallet and intensities than the "day" mode - it doesn't simply switch to another color like red. The background goes from white to orange-red for some pages and black for others and the graphics and numbers use all of the other colors, only in different hues, intensities and contrasts than in "day" mode.

Difficult to explain, and I don't have any pictures, but it is far different and better than any other instrument's "night" mode that I have seen. B&G really thought this out and it works brilliantly. "Red" was nowhere near their thinking on it. Like I said, even when left in "day" mode (with lots of white light) and the intensity turned down, it does not interfere much with night vision.

Our Simrad AP control head simply goes to red in "night" mode. It is unusable because there is poor contrast and the intensity needed to actually read it has to be turned up so high as to completely interfere with night vision. This is the same experience I have had with every other "red" night mode on other instrumentation.

On our boat, we find that the dim yellow indicator LED's on our electrical panel provide all the light we need for moving around and doing most non-writing, non-reading tasks inside the boat and do not interfere at all with our night vision. Again, this is an intensity thing, and not a color thing.

Mark
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