I recommend a compass that you can adjust for declination. The 9020G is a good start as is the Suunto M2.

My favorite is the Silva Ranger but you can expect to pay about $50.

Check out www.magnetic-declination.com for current declination info. Remember, many of the topo's available have declination data that is out of date.

Best of luck,

Blake

www.outdoorquest.blogspot.com

I disagree that adjustable declination is a necessary feature in a compass.

It's nice but, really, necessary for a beginner?

Knowing what the declination for the area is can be important but even that isn't truly necessary if you're using catch features and other orienteering-style methods. Surveying, yes, rambling the woods - not so much.

The USGS has made their topo maps into downloadable PDFs for free from their website. This means that you can get the study material for your favorite area at no cost and study them on your computer. I suppose sections can also be printed out (I haven't tried that trick yet).

Hopefully, the beginner will ascend to journeyman and eventually Grand Master status and may find the declination adjustment useful. In most of the country where I roam, the declination is about 15 degrees or so, but if I travel to the Pacific Northwest, I might want to tweak it a bit. It is just a nice feature that renders the compass a bit more versatile.

On my Suunto, the declination scale also serves a a clinometer, which can be extremely valuable in some situations.

One always has the option of simply navigating by magnetic north. With marine charts, where magnetic north is clearly indicated, that is often the best course to follow.....

If you always orient your paper map, then it doesn't really matter whether you're using a declination-corrected compass or a non-corrected compass. If the compass points in "that" direction in the real world, it will point in "that same" direction on the paper map. You just have to make sure you're using the correct North-South reference line on the map.

If your compass is MD-corrected, then you need to use a true North-South line on the map - typically this is a longitude line since they are always true north.

If your compass is not MD-corrected (pointing to mag. north), then you'll need to use the little magnetic north (MN) line on the map's north indicator symbol that shows true north (TN), magnetic north (MN), and grid north (GN).

Sounds good eh? Well, the problem is that most USGS topo maps are really old ... and the magnetic declination has changed since the map was published. That can sometimes be a fair amount.

While I DO orient my map to north before I use it, I prefer to use true north for two reasons: (1) because I find it easier to use the edge of the topo map (which is a longitude), than the lttle MN line, and (2) because that little MN line is typically off by some amount.

Does that amount matter? For finding trails and paths, no, probably not. But for doing triangulation, it can make a pretty big difference. If I carry a GPS, typically I'm not going to need to do triangulation.

Which brings up an even more important issue ... it is critical that you set up your GPS so that:

1. Your GPS datum matches the datum printed on your map. Most USGS topo maps use NAD27, though I'm told some are starting to use the GPS default of WGS84.

2. Make sure your GPS "North Reference" is set up to match your compass. If you have your compass adjusted for magnetic declination, set your GPS to "True North". If your compass is not MD-corrected, set your GPS to "Magnetic North". This is important if you use your GPS to calculate a heading to a waypoint.

BTW, Garmin provdes a pretty nice phamplet that introduces how to use a map, compass, and GPS together:

http://www8.garmin.com/manuals/UsingaGarminGPSwithPaperLandMaps_Manual.pdf

When I was a young Boy Scout I was taught to draw magnetic N-S lines on my map and only use those lines. This allowed me to use the map without orienting the map to north. It is much faster that way. Today I'll do the same thing but with true N-S lines and a compass that is adjusted for magnetic declination ... and a GPS set to "True North".

Be aware that little MN line on the symbol is diagramatic only! The number of degrees it states is good (as of the stated date), however the actual angle depicted is diagramtic only!

According to the USGS pamphlet Finding Your Way with Map and Compass:

"A diagram in the map margin
will show the difference (declination) at
the center of the map between compass
north (magnetic north indicated by the
MN symbol) and true north (polar north
indicated by the "star" symbol). This diagram
also provides the declination
between true north and the orientation of
the Universal Transverse Mercator (UTM)
grid north (indicated by the GN symbol).
The declination diagram is only representational,
and true values of the angles of
declination should be taken from the
numbers provided rather than from the
directional lines."

Eeek! I did not know that. Thanks!

Thi is all quite true, and definitely worth knowing. However, if one is referencing to terrain features, which is about 99% of the time, it is irrelevant.

Another great way to learn of the actual declination in your area is to get an aviation map - a "sectional." Those charts expire every 6 months so you may be able to get a free one at the small airport or from a pilot friend.

It would have the current (within 6 months) figure.

Indeed the USGS figures can't be right as many of the maps, at least the ones I look at, haven't been updated since 1960.

Jeanette

Here's a quick method for getting the mag declination of your location ...

First - can you post me the latitude and longitude of the town or city where you live? If that's too private, give me the lat and long coordinates for a major city close by you.

Pete2

I have been using the Online Declination Calculator from NOAA's National Geophysical Data Center when I need to find the declination for an area.

http://www.ngdc.noaa.gov/geomagmodels/struts/calcDeclination

from what I can tell it accurately covers a local park that has a declination 1.5 deg greater then just a few miles away. The values compare favorably with several major land marks you can see at quite a distance thanks to the local terrain.