What's your declination?

What's your declination? If your compass is equipped to adjust for magnetic declination (and it should be) the following link is very useful in finding the declination in your AO.

http://magnetic-declination.com/

As I have only used Brunton pocket transits for the last 40 years, I have no idea if other compasses are equipped to adjust the declination as Bruntons are, but I found the declination for my AO this morning and adjusted my compasses accordingly. Now, my compass needle, which points to magnetic north, also accurately tells me true north.

I use Cammenga Tritium Lensatic Compasses, exclusively.

Started using them waaaaay back in '67 when I first went into the green machine.

And of course , you can set the declination on them.

Bob
III

- 2 degrees 53 degrees W

I like women, that's my declination. Oh, you mean compasses. Not sure you can set it on mine.

I am -5 degrees, 25'w.

I learned something today I wasn't aware of. Your declination can change over time. I always thought I was about -4 degrees w. Glad to know that, something else to keep track of.

Also here is another link for finding your declination.

http://www.ngdc.noaa.gov/geomag-web/

Great post Grumpy

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Originally Posted by bacpacker

I am -5 degrees, 25'w.

I learned something today I wasn't aware of. Your declination can change over time. I always thought I was about -4 degrees w. Glad to know that, something else to keep track of.

Also here is another link for finding your declination.

http://www.ngdc.noaa.gov/geomag-web/

Great post Grumpy

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I read something about older FAA maps are wrong because of declination changes at certain airports, something like if you approach by the old headings you miss the runway by 20 feet or something to that effect.

I'll have to try and find it again, but I found a site that showed locations from the 1790's with the declination and updated it every ten years. I was surprised how much it varied. My locations went from around -2 degrees to almost -6 degrees during that period.

For short distances 2 degrees won't be off that much, but for several miles is can mean a lot.

Sounds about right. . .
Magnetic declination: -1° 30' WEST
Declination is NEGATIVE
Inclination: 71° 0'
Magnetic field strength: 55248.5 nT

Runway numbers are based on the magnetic heading of the runway, rounded off to the nearest ten degrees. Because the magnetic variation changes a bit (usually around 10-15 seconds of arc a year) every now and then, and usually because of the rounding over rules, the numbers need to change.

So, a couple times a year in the US, runways are closed for a day or two, the numbers painted over and then repainted. This is a big hassle if there is an instrument approach, since all of the approaches, charts, etc have to be re-surveyed and reprinted.

Thats actually interesting news Fidel, I did not know that!

I do my dec on paper and use a USGI lensatic. :-) Its what Im used to...

EB

I learned on a mil lensatic, but I use a Ranger or equivalent now.....lots easier, faster, and most PJ's I know use them as well.

Quote:

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Originally Posted by Fidel MD

I learned on a mil lensatic, but I use a Ranger or equivalent now.....lots easier, faster, and most PJ's I know use them as well.

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Could you link to the unit, Id like to learn more maybe shop...

Thx,
EB

Quote:

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Originally Posted by ElevenBravo

Could you link to the unit, Id like to learn more maybe shop...

Thx,
EB

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Sure. Standard orienteering style sighting compass, pretty much like this version (made by Suunto)....the actual maker of the three big orienteering compasses sold in the US is mixed up, since the local (US) names have rotated around the actual manufactuerers a couple of times.


http://www.rei.com/product/787189/su...-2-pro-compass

I actually carry three (or more) compasses in the field, because I've had them get f-d up (and with only two, how would you know which one?). When I was on a SAR team, I'd start each field exercise out by asking everyone to point out north to me....and then we'd actually get out compasses and find out. Most folks were way off, even when using major landmarks like Interstate-5.

My BoB has a full size like that one, two smaller ones like this http://www.rei.com/product/653748/su...hibian-compass and a couple of small/inaccurate ones, like one on my watch strap.

I also have a whistle (all plastic) on the lanyard for the compasses, and they have UTM grid readers on them as well. I keep a set of ranger beads, too.

You can make your own UTM grid readers. Get the files from these guys, print out a copy, and then xerox it onto transparency stock. If you want to get fancy you can laminate the sheets, then cut them out.

http://www.maptools.com/FreeTools/UTMtools.html

Standard Topo maps are 1:24,000 and 1:62,500 scales in the US, military standard sheets are 1:50,000 scales.

BTW, I have one of these in my Incident Commander box, and occasionally find it useful


http://www.amazon.com/Metric-Plastic...006232&sr=1-18

A Brunton is also known as an artilleryman's compass and can measure inclination. Typical geology mapping compass>

The various Silva Ranger/Suunto MC2/whatevers also can measure inclination, at least in certain models (the Silva Ranger CL, for example) http://store.silvacompass.com/baseplate-ranger-cl

Frankly, a feature I've found little use for.

I do have a couple of M2 mortar/artillery compasses (surplus) and a Brunton pocket transit http://www.brunton.com/products/inte...t-transit-0-90,


Some years ago I was able to purchase a Leitz transit, complete, which I have occasionally used in construction. It's much like this one (although in much better condition) http://www.ebay.com/itm/Vintage-Sokk...item3f2afba112 with the tripod, etc.

Fortunately, I remembered how to use it from a basic surveying class I took as an undergrad. Taking it out and using it is actually kind of fun, although the new stuff is so much simpler.

OBTW, when buying a compass make sure the one you pick in the store points pretty much in the same direction as the others....Ive seen the needles painted on the wrong end, more than once.

Also, if the store uses theft prevention tags, remove the compass from the packaging (or remove the tag) before they demagnetize it....I've known compasses to get scragged by the demagnetizer.

Cool info bud! Ive grown so found of the USGI, Id be lost with anything else... however there is this one time, in band camp... Er, wrong story... this one time I got a bum compass and had to do the land nav with a NESW wrist compass. We came in late but we used the "topo" map (off a copier none the less) with terrain features to actually do the course. We were scolded, until they finally verified the compass was waaay off. :-)

Speaking of grid lines, Ive tried for a LONG time to grasp LAT/LON but gave up... Then I discovered UTM and never looked back! Its MGRS, but for sillyvilians!! Easy as lard is greasy! I mastered the system in 5 minutes.

I have the NatGeo software from which I laminate the maps I make, and some grid tools from maptools.com (love them!), I also have my Dakota in UTM (Love that GPS!).

EB

I was certifying a dog handler as a NASAR Sar Technician once. The program required a compass course of around 1.5km, with 5 legs - the hard part was using pace counts to get the right distances, given the right headings. No electronics allowed.

This one woman for some reason absolutely wasn't doing it right, at any point. I know she was trained correctly (I trained her), she had demonstrated the right techniques in class, but absolutely could NOT get any leg right, even on direction. At first I thought her compass was hosed, so I gave her mine (which I knew was right) and she still couldn't do it.

So, in remediation I had her show me what she was doing - and she was going through the right motions, just getting the wrong results (and not just wrong, but inconsistently wrong - a different heading each time). Quite a puzzlement.

I made certain that she didn't have any metal on her - no radios, underwire bra, surgical implants (although they are not usually magnetic), any other metal. I had her ditch her pack, just in case - still no luck. Finally, I noticed that when my compass got close to her, it moved.....yep, she had her own, STRONG, magnetic field. Thats one of the weirdest things I've seen.

To get her through the class I had her tell me exactly what to do, I'd do the compass work and she could do the pacing. No problems.

Another time, I had a (former) USMC Force Recon give me crap about using orienteering compasses, instead of a mil-spec lensatic. I don't give a crap what anyone uses as long as they can successfully accomplish the exercise so I told him to use whatever he wanted.

Two hours later, he borrowed my orienteering style compass after failing the course 3 times. Oh, he also claimed that my course was laid out wrong - except I used that Lietz transit to lay it out, and everyone else was accomplishing the course OK.

Use whatever you are good with.


As far as grids go, I taught myself marine navigation when I was around 12, and celestial when I was 15. I was very happy to learn MGRS/UTM in the military, though.

And I've found that giving UTM grids to people who should but don't use it is counterproductive :)

In my salad days as an exploration geologist I mapped abandoned mines, drilling prospects, open pits and just general geologic mapping using my Brunton to measure the attitude of beds, foliation and fault planes. I've laid out claim lines with it and used it to signal with. For me, a Brunton was, and is, as much a part of my tool kit as my rock pick.

In boy scouts I used other compasses, but for me, I'll take a Brunton over anything else. It is the tool I am most familiar with.

BTW,when I bought my first International model, it was only about $100.

I like this thread! Diggin it!

EB

Anyone here have any experience with geocaching?

I did a little when I first got my gps but found it too easy, so I kinda just forgot about it.

That's kinda what I thought. Might be nore challenging with a compass and a topo-kinda like old style orienteering.

Grumpy old man... I geocache in the regular. Yeah, many are pretty easy to find, but I love the challenge of not being spotted. I also like all the different types of caches and the travel bugs.

I get really stoked when I find the out of the way ones (on an island down the river, etc)

Caveman... since you are in the area... I will give you the gps coordinates for a geocache that I set up 6 years ago... that has yet to be found. you like a challenge????

I guarantee you, your forey around Pinawa, will be less than a... well less than anything...

I challenge you!

T.

Ooh ooh.... Gimme gimme. Challenge accepted! I'm always up for a little fun @sniper-t

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Originally Posted by Caveman Survival

Ooh ooh.... Gimme gimme. Challenge accepted! I'm always up for a little fun @sniper-t

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bwahaha!

I will verify its continued existence at the end of Sept... and post the GPS co-ords here... You will have until the end of the calendar year to find it...

Assuming you accept this challenge...

Woot! :)

Pack for 3 days WAY remote!!!

time is getting close... got the canoe shined up? tent dusted off? insurance paid up? lol

make sure you let us know when you are heading out... So I know when to come and rescue you... ;)

I await the magic numbers!

50 53.823
095 33.398


North, then West... obviously.

Have fun and take pics!

Once you find that one, here are a couple others that I found:

50 44.383
095 35.639
there is some snare wire in this one, because if you find it, you may want to hang yourself rather than trying to get back out

50 49.460
095 33.207
A tough one unless you can think outside the box...

Since you are a local outdoorsman, I will share a favourite fishing hole.

50 35.571
095 17.157
decent tackle box here, use what you want, add something before you leave.

53 44.949
099 28.385
I know you are not a hunter... yet, but this one is amidst some of the finest grouse shooting area that I have ever been on. This cache is tough to find, surprisingly, because it is a small footlocker. Take a box of shells that you don't want or need, and exchange it for a box there. No handloads, please.

enjoy!

Sweet @sniper-t . I'll be planning my adventure now

bump...

Anything to report?

And.............................?

Hope he's not lost out there... I'm not planning to head up for another 6 weeks...

Hey CS... I'm heading up in a few weeks... you available for an expedition?

Sorry for lack of update. Shit got busy on me and I didn't get a chance to make good on this by calendar's end.... It will be conquered though.... It's a mission now

mwahahaha...