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Thread: Compass Recommendation

  1. #16
    Senior Member Nessmuk's Avatar
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    Quote Originally Posted by iAmKrzys View Post
    IMHO the super accurate markings on a compass are of limited use.
    I have practiced and taught courses in land navigation for more than 20 years, and I completely agree with IAMKrzys's analysis. If you become proficient at observational navigation and terrain association, you don't need micrometer accuracy on a hiker's orienteering style compass. Save that for land surveyors and legal boundaries.

    Back in the day when I was an Air Force navigator (when the AF actually used navigators). On a precision navigation course, I might have said "pilot, turn 2 degrees left". Pilot: "Nav, I can't do 2 degrees". Navigator:"Ok, turn 5 degrees left". Pilot:"OK, turning 5 degrees left". Nav: "Pilot, Now turn 3 degrees right". Pilot:, "Nav, Ok, I can do that". It worked better on the younger pilots.
    Last edited by Nessmuk; 02-13-2018 at 09:19 AM.
    "She's all my fancy painted her, she's lovely, she is light. She waltzes on the waves by day and rests with me at night." - Nessmuk, Forest and Stream, July 21, 1880 [of the Wood Drake Canoe built for him by Rushton]

  2. #17
    Senior Member hikerbrian's Avatar
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    It has been a LONG time since I did high school geometry, but my calculations tell me that if you were off by 1 degree, you'd be off course by 92 feet over the course of a mile. Two degrees off course would result in a 184 foot 'miss' of the desired location. I imagine planning for plus-or-minus 3 degrees is reasonable, absent any terrain features, and with a good compass and careful attention.

    In practice, that means (for example), if you are trying to get back to your car, which is parked on the side of the road, you probably want to aim 3 degrees to one side or the other. That way, if you get to the road and don't see your car, you know which direction to walk. If your navigation was perfect, you'd have to walk the road for 276 feet (~1 football field). If you navigated erroneously by 3 degrees in the 'good' direction, your car would be right in front of you. And if you were off by 3 degrees in the 'bad' direction, you'd have to walk 2 football fields. But you'd always know which direction to go on the road. Any of those would be preferable to walking endlessly down the road, not knowing if your car was in front of you or behind you.

    Of course, being able to use 'terrain handrails' is highly preferable. More fun, too, IMO. I love connecting what I see on my map and compass to the physical world in front of me. Park your car next to a stream. Or at the height of land. Save yourself a couple of football fields.

    Nessmuk, that is pretty hilarious!
    Sure. Why not.

  3. #18
    Senior Member Nessmuk's Avatar
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    Quote Originally Posted by hikerbrian View Post
    It has been a LONG time since I did high school geometry, but my calculations tell me that if you were off by 1 degree, you'd be off course by 92 feet over the course of a mile. Two degrees off course would result in a 184 foot 'miss' of the desired location. I imagine planning for plus-or-minus 3 degrees is reasonable, absent any terrain features, and with a good compass and careful attention.

    Of course, being able to use 'terrain handrails' is highly preferable. More fun, too, IMO. I love connecting what I see on my map and compass to the physical world in front of me. Park your car next to a stream. Or at the height of land. Save yourself a couple of football fields.
    Think radian measure trigonometry. The resulting rule of thumb is for every degree of course error (for relatively small angles), you will be offset by 1 part in 60 in cross track error per distance traveled. For example, (keeping the math easy) for a 3 degree error over 6000 feet (nearly a nautical mile), 1 part in 60 is 100. 100 x3 puts you 300 feet in cross track error at your destination.

    Handrails, catches, and backstops. Look for them always to assist your navigation technique. Even if you have to zig-zag to a final destination, there are almost always these features to help you reach definitive intermediate fixed points to help you along your way. building in Intentional offsets are an excellent technique to help you determine which way to turn at a linear backstop.
    Last edited by Nessmuk; 02-13-2018 at 10:32 AM.
    "She's all my fancy painted her, she's lovely, she is light. She waltzes on the waves by day and rests with me at night." - Nessmuk, Forest and Stream, July 21, 1880 [of the Wood Drake Canoe built for him by Rushton]

  4. #19
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    The old trick when coming out to a road is if there are power poles figure out which way the numbering runs and then note the closest pole number where you started.

    Of course these days I expect most folks would just look at the GPS screen and follow the electronic "crumbs" back to the car.

    A general observation I make is most people new to map and compass occasionally blow the declination adjustment and frequently end up doubling the error. With 17 degrees declination that is over a 30 degree mistake in bearing.

  5. #20
    Senior Member Nessmuk's Avatar
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    Quote Originally Posted by peakbagger View Post
    A general observation I make is most people new to map and compass occasionally blow the declination adjustment and frequently end up doubling the error. With 17 degrees declination that is over a 30 degree mistake in bearing.
    The most important aspect of learning map and compass together is to understand the declination diagram, how to interpret what it means, an how to apply what it tells you. Everything you need to know is in that diagram. A glance at the diagram and logic will tell you what to do with your compass azimuth with the map. If your map does not have a diagram drawn on it (USGS 1:24K maps have it, 1:25K maps do not - but the dec is given in the legend), then draw one on it yourself.
    Last edited by Nessmuk; 02-13-2018 at 11:21 PM.
    "She's all my fancy painted her, she's lovely, she is light. She waltzes on the waves by day and rests with me at night." - Nessmuk, Forest and Stream, July 21, 1880 [of the Wood Drake Canoe built for him by Rushton]

  6. #21
    Senior Member DayTrip's Avatar
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    Quote Originally Posted by iAmKrzys View Post
    IMHO the super accurate markings on a compass are of limited use. Maybe if you are on a top of a mountain where you know exactly your position and you try to distinguish between two peaks far away from you but otherwise clustered nearby then maybe that 1 degree scale and notch & reticle sighting can help you determine what you are looking at. When it comes to off-trail hiking the reality is that in any nontrivial terrain walking in a perfectly straight line is almost impossible and that 1 degree won't matter anyways. If you have some time to spare do this experiment - go to some unfamiliar place where you could walk for half a mile in the woods to some landmark (e.g. a trail intersection) get a bearing from your map or gps and try to walk directly to this point using compass. Don't look at your gps until you think you walked for 0.5 mile and then review your track. Contrast this with 1 degree deviation from straight line.
    Interesting. I noticed that most of the authentic military compasses had a resolution of only 5 deg, which I was surprised by. I'm sure the uncertainty of taking a bearing is pretty large between holding the compass level, reading the bearing, lining up objects and then doing this many times over the course of a segment. I almost never look at the map on my GPS. When I am using map and compass I primarily use the GPS to reference my elevation so I generally have a very good idea of where I am on the map. I also like to pre-plot key waypoints in it at home when I plan a hike so I can get an instant bearing to key landmarks without having to estimate my position, plot on the map, etc. I'll add others along the way at known places for the same purpose. Major time saver, especially in windy or foul weather or the dark where handling a map is difficult or impossible.

    When I am out purely experimenting and brushing up on my skills near my house I like to do what you described by following terrain only based on map and estimating my position from time to time. Periodically I will compare my estimate against the GPS map to confirm how accurate I was. When I get home I'll load the GPS file in CalTopo and compare what I did against what I thought I was doing. Very helpful learning experience. Not surprisingly, my most "typical" error is getting the elevation wrong and miscalculating my position because I forgot to calibrate the GPS to a known elevation before I started. Stupid technology.
    NH 48 4k: 48/48; NH W48k: 46/48; NY 46: 5/46

  7. #22
    Senior Member DayTrip's Avatar
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    I am familiar with baselines, handrails, intentional offsets and all that stuff. My goal for the resolution is to be able to read it, not navigate onto the top of a pin. The 2 deg marks on my compass now seem pretty close to a solid black line for me so magnifying it, or having more marks to use to identify the number would help.

    hikerbrian - the 92' for 1 deg is a little misleading (although I agree with your overall premise) because it assumes you take 1 bearing and walk in a perfectly straight line on it. It is highly likely in the woods that you would take many bearings over the course of the mile, building an error into each one. And that 1 deg I bet is almost never that accurate with a normal compass. The distance between two marks is 2 deg but is so small that accurately assessing a 1 deg error is unlikely. And the magnetic declination adjustment on most compasses is microscopic and (at least on mine) is 2 deg increments as well, another source of error. (or worse in the case of manually doing off an arrow diagram on the map with no markings). And then there is the matter of taking that theoretically accurate bearing and then walking exactly on that line. When adding up all these uncertainties I would expect even an "accurate" actual path of travel could easily miss a target by hundreds of feet. That would be an interesting experiment actually. Plot a waypoint in GPS that is a mile from a start position. Take that actual bearing by GPS and then physically walk it to see how close you came to the actual target after walking one mile. I think I might try that.

    Neesmuk - The area near my house I experiment in the most has a series of virtually identical wooded parallel ridges running West to East. Simply reading the terrain, even with an elevation known, is not enough to know one'e location. And the ridges all have sub-ridges that are not large enough to see on 20' contour intervals and the hollows have swampy areas or brooks that are virtually identical. So often keeping track of these involves a count of how many ridges I have traversed, use of other features like unmarked paths, etc. You can't just break out the map mid-hike and identify the terrain to see where you are without doing a little exploring. You really have to pay attention from the beginning so you have a point of reference.

    I had an interesting argument on Facebook awhile back with a guy who boasted that using just the stars he could navigate to a spot 10 sq ft in size (roughly a 3.2 ft x 3.2 ft area). I not so politely responded that this claim was total nonsense so he chronicled a story about how he found a well 50 or so miles from where he was right down to the edge just by the stars. I asked him if he saw the well as he approached it and he said "Well, yah". So I offered to provide him with a non descript, landmark free patch of pine needles near my house with a frisbee on it to see if he could find it with just stars. And then the back pedaling began. He obviously used a visible landmark to reorient himself. And of course we do the same thing. We might be 150' off target but then see what we were looking for and we walk toward it. We didn't "bulls eye" the landmark.
    Last edited by DayTrip; 02-13-2018 at 06:39 PM.
    NH 48 4k: 48/48; NH W48k: 46/48; NY 46: 5/46

  8. #23
    Senior Member jniehof's Avatar
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    Quote Originally Posted by DayTrip View Post
    I had an interesting argument on Facebook awhile back with a guy who boasted that using just the stars he could navigate to a spot 10 sq ft in size (roughly a 3.2 ft x 3.2 ft area). I not so politely responded that this claim was total nonsense
    My math could be off, but that means he was claiming to be able to tell the position of a star to 5mas with the naked eye. Hubble's resolution is about 50 mas. Nonsense doesn't begin.

  9. #24
    Senior Member iAmKrzys's Avatar
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    While I don't have a specific recommendation for a compass with highly visible markings I can add that I carry this whistle / thermometer / mini compass / magnifying glass combo: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 It is a bit on a cheap side (price & quality) but the magnifying glass is useful for checking if that tiny spot on my leg is a miniscule deer tick nymph or something else...

  10. #25
    Senior Member Nessmuk's Avatar
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    Quote Originally Posted by DayTrip View Post

    Neesmuk - The area near my house I experiment in the most has a series of virtually identical wooded parallel ridges running West to East. Simply reading the terrain, even with an elevation known, is not enough to know one'e location. And the ridges all have sub-ridges that are not large enough to see on 20' contour intervals and the hollows have swampy areas or brooks that are virtually identical. So often keeping track of these involves a count of how many ridges I have traversed, use of other features like unmarked paths, etc. You can't just break out the map mid-hike and identify the terrain to see where you are without doing a little exploring. You really have to pay attention from the beginning so you have a point of reference.
    Exactly. You can't drop someone in the middle of what I might call "confused terrain" with a map that looks basically the same everywhere and tell him to pinpoint his current position. just like driving to work in the morning, you begin at a known place, then navigate by known objects, road signs and intersections, etc. to get to your work place. If you dropped me in the middle of New York City (please no) on a random street with just a street map, I could probably eventually identify the Empire State Building and maybe a few others that I have seen previously or seen pictures of and then using the map I could find my way around from there. the same applies if I am dropped within visible sight of the distinct shape of Blue Mountain, or the shore of a lake with an identifiable shape I know.

    Most of where I navigate is in the relatively lowland features of the western Adirondacks. There is not much major elevation change, so using elevation in that sense to navigate is not a usual priority for me. When I am standing on top of a hill, I am up high. When I am in the bottom of a ravine, I am down low. Map contours will help me with that. That's all I need to know.

    I will often navigate along the side of ridges (although walking the crest is usually much easier) by counting the draws, ravines, and spurs that I traverse until I reach a definitive landmark that is also shown on the map. Maybe it is a bend in a stream or draw, maybe it is saddle point in the ridge or a steeper than usual rock face. From that known point forward, navigation starts anew to the next identifiable point.

    The starman's claimed accuracy is definitely bogus. I flew as an Air Force navigator in my younger years. I used a sextant and thick books with tables of calculations from which I put star measurement data on a page of manual calculations. Getting a star fix (my location) to less than a nautical mile of error would be a rare event. In most cases I would be happy to get within a couple of miles of truth, even during several navigation competitions I was in. Close enough for the task at hand, but everything had to be perfect to get better than that.
    Last edited by Nessmuk; 02-15-2018 at 01:59 PM.
    "She's all my fancy painted her, she's lovely, she is light. She waltzes on the waves by day and rests with me at night." - Nessmuk, Forest and Stream, July 21, 1880 [of the Wood Drake Canoe built for him by Rushton]

  11. #26
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    Staying found is easier than figuring out where you are once you are lost. Before gps, we’d shoot back azimuths from two different points that were known to us. Plot the two lines on the map and where they intersected was where we were located.

  12. #27
    Senior Member Nessmuk's Avatar
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    Quote Originally Posted by egilbe View Post
    Staying found is easier than figuring out where you are once you are lost. Before gps, we’d shoot back azimuths from two different points that were known to us. Plot the two lines on the map and where they intersected was where we were located.
    Of course, that is an old well known method of finding your location by drawing lines of position (LOPs). Most people might call it triangulation, technically it is the method of resection. Most useful only if you have a clear view of two or more known distant terrain objects (map identifiable peaks, for example) from an elevated location. In dense woodland forest such as where I hike in most places outside of the high peaks in the Adirondacks, those geographic objects are rarely available for viewing through leaf cover. Fortunately there are plenty of other methods for successful precision navigation.

    If you are standing on or near a known linear terrain feature (along the top of a ridge, or on a road, or on the edge of a lake or river), you already have one LOP. You may be able to get away with viewing only one known distant object, ideally at a near 90 degree angle from the line of your linear feature. This method is called Modified Resection.
    Last edited by Nessmuk; 02-15-2018 at 02:02 PM.
    "She's all my fancy painted her, she's lovely, she is light. She waltzes on the waves by day and rests with me at night." - Nessmuk, Forest and Stream, July 21, 1880 [of the Wood Drake Canoe built for him by Rushton]

  13. #28
    Senior Member hikerbrian's Avatar
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    Quote Originally Posted by DayTrip View Post
    When adding up all these uncertainties I would expect even an "accurate" actual path of travel could easily miss a target by hundreds of feet.
    Daytrip, sorry if I wasn't clear, but that's exactly the point I was trying to make. If you're really good with a compass, have a very good compass (i.e. well constructed and with a mirror sight), and pay careful attention, you still better expect to be off by 3 degrees (276' or about a football field, after 1 mile). According to Nessmuk, that's what military navigators - folks on whom life and death itself rests - that's what they go for. Much better to have some terrain features to work off of. Absent terrain features, one better understand the challenge they're undertaking and consider carefully the consequences of missing their mark.

    I personally prefer to manually add (or subtract) declination with each reading. I doubt this adds more than a degree of error (and I rarely need to be THAT accurate anyway). I find this exercise to be quite trivial.

    I've had to navigate by compass in very bad conditions on several occasions. It is not a party. The problem isn't so much getting a good compass bearing, it's that if you're in that situation - above treeline, for example, off trail and with zero visibility in heavy wind and blowing snow - well, you're probably just not having a very good time. For trips where I may possibly NEED my compass to save my a$$, the compass lives around my neck and my map is pre-folded to the day's itinerary in a clear bag/case attached to my hip. With this setup, I can use my body as a wind shield, the map bag provides enough rigidity to resist the wind (a second set of hands helps a lot in this situation), and I can get a good bearing in less than a minute. This is a photo from a Presi-traverse attempt a few years ago, during the 1 hour of decent visibility we had on that trip, so you can see the set up:
    Click image for larger version. 

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    The situation I try to be ready for is the one we read about a few weeks ago - the woman needing rescue in Ammo Ravine. She didn't need to be accurate within 3 degrees; probably within 10 degrees, combined with the terrain features, and she would have been fine. OTOH, finding the top of Lion Head is really pretty hard, and the consequences of missing are severe. So is finding the entrance into the trees from Bondcliff heading up Bond.
    Sure. Why not.

  14. #29
    Senior Member Nessmuk's Avatar
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    I am told this is a pretty good read.

    http://www.adkhighpeaksfoundation.or...navagation.php

    enjoy.
    "She's all my fancy painted her, she's lovely, she is light. She waltzes on the waves by day and rests with me at night." - Nessmuk, Forest and Stream, July 21, 1880 [of the Wood Drake Canoe built for him by Rushton]

  15. #30
    Senior Member DayTrip's Avatar
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    Quote Originally Posted by hikerbrian View Post
    Daytrip, sorry if I wasn't clear, but that's exactly the point I was trying to make. If you're really good with a compass, have a very good compass (i.e. well constructed and with a mirror sight), and pay careful attention, you still better expect to be off by 3 degrees (276' or about a football field, after 1 mile). According to Nessmuk, that's what military navigators - folks on whom life and death itself rests - that's what they go for. Much better to have some terrain features to work off of. Absent terrain features, one better understand the challenge they're undertaking and consider carefully the consequences of missing their mark.

    I personally prefer to manually add (or subtract) declination with each reading. I doubt this adds more than a degree of error (and I rarely need to be THAT accurate anyway). I find this exercise to be quite trivial.

    I've had to navigate by compass in very bad conditions on several occasions. It is not a party. The problem isn't so much getting a good compass bearing, it's that if you're in that situation - above treeline, for example, off trail and with zero visibility in heavy wind and blowing snow - well, you're probably just not having a very good time. For trips where I may possibly NEED my compass to save my a$$, the compass lives around my neck and my map is pre-folded to the day's itinerary in a clear bag/case attached to my hip. With this setup, I can use my body as a wind shield, the map bag provides enough rigidity to resist the wind (a second set of hands helps a lot in this situation), and I can get a good bearing in less than a minute. This is a photo from a Presi-traverse attempt a few years ago, during the 1 hour of decent visibility we had on that trip, so you can see the set up:
    Click image for larger version. 

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    The situation I try to be ready for is the one we read about a few weeks ago - the woman needing rescue in Ammo Ravine. She didn't need to be accurate within 3 degrees; probably within 10 degrees, combined with the terrain features, and she would have been fine. OTOH, finding the top of Lion Head is really pretty hard, and the consequences of missing are severe. So is finding the entrance into the trees from Bondcliff heading up Bond.
    That's OK. I thought you were arguing the reverse the way I first read it: that it would be hard to miss your mark because you'd be less than 100' off because 1 deg error over a mile is not that big a deal. Not that I do any hard core navigating but I usually do the same thing as you: wear the compass on my neck and carry map in some sort of protective case in a chest pocket for easy reading (usually a sheet protector but I have a "hard core" case for bad weather). I love CalTopo for this. I usually print maps of my itinerary so I can scribble all over them, take notes, etc and I can blow up areas so features are easy to read. I keep a little overlap from page to page and just switch sheets as the area changes. Keep the real map in pack as a back up.

    I currently have my compass adjusted for declination but I'm starting to waiver back toward the school of thought that it is easier to add/subtract the declination from each reading. Declination in all the areas I have hiked is rarely more than 1 1.5 deg different but it is still a small error built into my readings having it preset. (My compass needs a tiny jewelers screwdriver to adjust declination which combined with my diminishing vision ensures I never adjust it ).
    NH 48 4k: 48/48; NH W48k: 46/48; NY 46: 5/46

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