I have a trusty old Garmin 60CSx which has served me well for years. I was wondering about something very basic -- can the unit be set to display true (as opposed to magnetic) readings so you can follow it like a compass (remember those?) after you have adjusted the compass for magnetic declination. I guess I never have to follow a direction line with great accuracy in most of my usage. I'm mostly a "just go more-or-less east to avoid that cliff" sort of user.
I know it has two methods to determine directions: 1) magnetic (you push a certain button and then turn slowly in a circle) and 2) direction of travel as determined by your movements (which won't work if you stand still).
Declination from a topo map (remember those?) is available but of course variable - it changes from place to place and from time to time, but since on-line topo maps are WAY out of date, the information from these maps is not helpful.
The GPS could, in principle, get the readings for your current position from some database and do the correcting for you. There is probably an on-line site with up-to-date information published by NOAA but I haven't bothered to find it or utilize it.
If not my 60CSx, anything for a newer model? From a smart phone?
Thanks
I sense a couple of misconceptions in your post. Yes, you can set the 60CSx to display heading or desired course relative to either magnetic or true direction. Don't confuse that setting with the GPS determining direction by having it operate as an electronic magnetic compass, vs as a GPS compass (in which case you must be moving for it to properly display direction). Personally I never use a GPS in calibrated electronic magnetic compass mode. I will always use a real compass for that function. But if you are following the GPS when it is on the compass display page, it doesn't matter whether the compass is set to display in magnetic or true reference. When the red arrow in the display is centered, it will take you to the entered destination waypoint. The actual heading value, or azimuth, will display in whichever reference you have previously set in the GPS, as true or magnetic. I don't know for sure, but I believe the declination value that the GPS uses in its database is updated with updates to the GPS firmware.
That's the same if you are navigating by real compass alone - if you are given a magnetic heading to a destination, you don't need to convert anything to use a basic manual compass - just dial in the mag heading and go without regard to declination. If you are given a true reference heading to follow, then either convert with declination using simple math to get the local mag heading, or with a compass properly adjusted for local declination.
Declination only comes into play when you are transferring measured azimuth information to or from a map to a compass, or vice versa. Then it is important to know if the reference from the map is measured in true or magnetic. It is true that many USGS maps are quite dated, and that magnetic declination wanders from year to year. But in most cases the wander is a small value error, and even over a couple of decades in the lower 48 states it shouldn't differ by more than a degree or two from the declination diagram on the USGS map. If you navigate in part by terrain observation techniques, that small annual random declination error should not make any real difference. There are a couple of online resources that will calculate current declination, and year to year variation.
http://www.ngdc.noaa.gov/geomag-web/#declination
http://www.geomag.nrcan.gc.ca/calc/mdcal-en.php
GPS is an obviously extremely useful navigation tool, especially for work related activities such as SAR or accurate feature registration for map publication. But, at least for me personally, reliance on GPS will never replace traditional navigation techniques with map and compass when I travel for recreation in the backcountry. Current multi-day Land Navigation courses taught to law enforcement and SAR and EMT personnel at the NY State Homeland Security Preparedness Training Center are all about navigation with map and compass, with only a very minor session to introduce the most basic concept of GPS.
