I have seen conflicting comments about the utility of "GPS altimeters" - those fixing the altitude solely by GPS geometry and not utilizing barometric correction. While some claim that this is quite inaccurate, I have found that my bare bones receiver, a Garmin Foretrex 101, is actually quite accurate.....

Thus, a GPS derived elevation may be spot on....or may be as much as 100 ft (30 m) off.

For most practical purposes in wilderness navigation, a error of this magnitude is usually rather insignificant, say in climbing to a 10,000 foot high pass, or a 13,000 high mountain.

My experience has been that while I usually don't need the GPS and compass......when I do need them ....I need them really really bad! Which is why I carry them.

GPS doesn't know what direction it is pointing when it is not moving, or is moving very slowly. Thus a supplemental compass might prove useful.

Not always true. More modern GPSr have multi-axis compasses and give accurate direction even when motionless. My Garmin 62s for example. I do have to remember to recalibrate the compass after every battery change tho. But no matter what I always keep at least one magnetic compass with me.

My Garmin manaual says that you have to recalibrate the electronic compass each time you turn on the GPS. So I wouldn't trust it. Nor does it's built in barometer/altimeter ever work right.

[quote=AKSAR] and that you have already traveled 8.32 miles of the 13.2 you need to cover. Not vital to know, usually, but still fun.

I suspect that I'm one of the few folks you'll find here that actually PREFERS my GPS's to have electronic compasses. My reason is simple - this allows the GPS to continue to "point" to a waypoint even when I'm standing still.

Yes, I can use a magnetic compass, and carry one (or more) with me, and know well how to use it, but I tend to prefer tools that keep things as "automated" (simple) as possible so that if I'm tired or confused the arrow will be pointing in the correct direction, I can make proper decisions. Think of it something like the recommendation to be able to use gear one-handed - knife, light, PLB, ...

Yes, I know that a GPS can fail, or the batteries can go dead. I've had both happen to me. The former with a Garmin Nuvi while driving through a thunderstorm in the middle of an area in Detroit that I was completely unfamiliar with (uh oh), and the later while doing Geocaching with a group of Girl Scouts (its embarassing to borrow a few spare batteries from a Girl Scout - sigh). Typically I carry extra batteries, but in that case they were left at camp.

Then again, I'm also a person who will only accept adjustable declination on my magnetic compasses. A declination scale or doing the mental math is not something I want to do.

I rarely calibrate the compass in my Garmin GPSMAP 60CSx, and it points correctly. Heck, recalibrating it is a pretty simple matter - walk around in a little circle until it beeps - simpler than using a magnetic compass.

I'm not so sure that there is a power consumption concern with the electronic compass. A while back a few people on the geocaching.com forum did some direct power consumption measurements, and here are the results he posted (the power consumption for the electronic compass was negligable). The big power drain was the backlight - if used. The best way to minimize power consumption is to only turn it on the GPS when truely needed - as opposed to keeping it on to capture track information:

Garmin eTrex Vista HCx (fresh alkaline batteries)
69 mAmps - backlight off, WAAS off, electronic compass off
70 mAmps - WASS turned on
70 mAmps - WAAS on, electronic compass on
98 mAmps - GPS radio off
235 mAmps - backlight on

Garmin eTrex Venture Cx (rechargable batteries):
77.4 mA - GPS radio on, Backlight off
144 mA - GPS radio on, Backlight medium
220 mA - GPS radio on, Backlight high
48.6 mA - GPS radio off, Backlight off
108 mA - GPS radio off, Backlight medium
185 mA - GPS radio off, Backlight high
No difference WAAS on or off
From http://forums.groundspeak.com/GC/index.p...p;#entry3123403

I'd prbably be more inclined to appreciate the electronic compass in my Geko 301 and GPSMAP 60CSx if Garmin designed it so that you could turn it on and off without running through a hierarchical menu. A toggle "menu" on the 60CSx compass page would be very useful. As it is I always leave it turned off.