birding-aus

using GPS units for not getting lost in the scrub

To: "Vicki Powys" <>
Subject: using GPS units for not getting lost in the scrub
From: "Tony Russell" <>
Date: Fri, 12 Oct 2001 10:36:28 +0930
Ok Vicki, and further to Frank's note, this is what I do.

As I leave my car I take a fix with the GPS and SAVE it and note the number.
I take my compass with me as a back up.

When I wish to return to the car - as Frank says, leave it where you can SEE
it along the road - out with the GPS, let it take a fix where you currently
are, SAVE it, then go through your waypoint list  ( waypoints are the same
things as landmarks), highlight  the saved one for your car, press enter,
and press GO TO.
It will then give you the bearing (direction) and distance to your car. If
you then don't know how to use the GPS as a compass get out your normal
compass, wait till it settles and then look to see which direction the
bearing given by your GPS is. Note a landmark ( a tree or hill etc) in that
direction and walk to it. To check whether you are on track just do the same
thing a few times on the way back. This will get you to within a few metres
of your car. Practice it first in a big open paddock where you can practice
without getting flummoxed.
Most GPS's have what's called a moving compass facility which works exactly
like an ordinary compass but if you're not confident with it just use the
method described above.  It's also good practice to take a compass with you
anyway, just in case the GPS batteries fail.

To use a compass without a GPS is quite easy too.  As you are about to leave
your car get out your compass and get a bearing of the road or a fenceline,
say it's North/South.  Facing north, if you go left you will be walking
west, if you go right then you'll be walking east. Let's say you've gone
east.   Once lost what you do is get out the compass and look for
north/south. This doesn't tell you how far you've come or whether you've
walked in a straight line east, but it does put your orientation parallel
with the road or fence. So, if you've walked east away from the road you now
need to do the opposite , ie walk west, to return to it.  You won't hit the
road or fence exactly where your car is because the chances of having walked
at an exact right angle are very slight, but it will get you back to the
road/fence.
If you can't see your car you may be some distance from it and the next
problem becomes to decide which way to walk, left or right, just as Frank
described.  If there is traffic you could hail someone and ask whether
they've just seen your blue Maserati and if they say no, they may even give
you a lift in the direction they are going. Another reason to leave your car
where it can be seen.

Having been lost  (ONCE) myself I now take these precautions. I also look to
see where the sun is and which way it is moving ( it goes to the left) and
allow that it will have moved a bit before I get back. So if it's in front
of you but a bit left as you go in, it needs to be behind you and a bit more
to the right coming out.  I also look at clouds if there are any to see
which way they are moving, and a breeze can be a useful helper too, but
these last two can be subject to change of course at short notice.

The one time I did get lost ( overcast sky, no breeze, no compass, no GPS,
complete idiot, and it rained ) I just sat down and waited until I heard
some traffic. Then I bisected the start and finish points of the sound and
walked straight out to the road I had left.  One good trick when lost is
don't keep walking. Stop, sit down, listen and think. You may just hear or
see something which gives you a clue.

Of course if you are completely stuck, call me on your mobile, tell me where
you are, and I'll come and rescue you in my helicopter.

Tony.





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