Re: Garmin Etrex altitude question

On Mon, 13 Feb 2006 00:43:02 -0000, "NickM"
<njm@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

I want to buy an Etrex GPS for use in alpine 4000mer mountaineering. With
just 17 summits left to go, one or two recent experiences of incorrectly
determining altitude on ridge descents in whiteout have shown the importance
of knowing one's height.

I'd welcome anyone's experiences of using the basic yellow Etrex model to
gain elevation data. I know it only gives satellite-derived elevations, and
needs a reasonable view of the sky to do this. But how good is it in
practice, and what are its limitations? Rubbish under overhangs, I
appreciate.

All the upmarket Etrex models with in-built, self-calibrating barometric
altimeters and daft stuff like compasses (Summit, Vista, Geko 301) have
relatively short battery life, except for the very expensive VistaC with
colour screen.

So its either £60 odd quid for the basic yellow Etrex, or well over £200 for
the newest VistaC.

I'd go for the basic model if I knew it would do the job OK.
Any advice would be welcome.

I've used the Etrex in the Alps, but never felt the need to check the
altitude on it. Why bother with altitude when you can have a set of
accurate coordinates for your location?

In hilly/mountainous areas I find it accurate on horizontal location,
but it can on occasions be poor on altiude (up to 200m error IME)
presumably because surrounding mountains block out the satellites that
are low on the horizon and therfore more useful in deterrmining
altitude, i guess this would be less of a problem on high ridges.

To be honest the GPS feature I use most in the mountains is the
satellite display screen where you can actually see which satellites
are visible to the GPS which are below the horizon therefore you can
determine where in the murk the surrounding hills and valleys are.
Its a sort of cheap and cheerful radar unit ;)

Regards

Tim Jones
.

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