"Frogwatch" wrote in message
...
On Jan 4, 10:27 pm, "mgg" wrote:
"Frogwatch" wrote in message
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On Jan 4, 8:00 pm, Wayne.B wrote:
On Mon, 4 Jan 2010 14:39:09 -0800 (PST), Frogwatch
wrote:
I resolve to carry a compass even on
short trips into the woods from now on.
A pocket GPS is even better, and useful in the dinghy also.
In deep woods, GPS often has problems and does not work at all in
caves.
I have to wonder how well a compass would work in some caves as well.
Depending on the composition of the rock, it could drive a compass whacky.
Here's a thought... carry both! ;-)
--Mike
My compass has never failed me. Most caves are in limestone so
compositioin does not change the earths mag field.
Limestone.... I did not know that.
My only experience with caves is:
http://www.mercercaverns.com/ which is
limestone as well. I didn't know it was the norm though. Very cool tour
there as well. I doubt it's your cup-o-tea since they built steps. ;-)
--Mike