crazy log!

I wonder if anyone else has had this kind of experience?

My hiking group did a shore walk from Kahuku to a member's house
just past Turtle Bay on O`ahu last week. Not the sort of thing one
really needs to track with GPS--you could just draw a line at the
edge of the ocean on a map with a pen--but I kind of like to have
a log file for every hike I do.

According to my Magellan Explorist 500 we finally got underway
after car-pooling to the starting point at 9:56 am:

$PMGNTRK,2140.761,N,15756.743,W,00019,M,195623.44,A,,280109*65

Things went fine for five miles, reached at 12:05.

$PMGNTRK,2141.988,N,15800.041,W,00016,M,220527.16,A,,280109*66

Then, according to the track log, I was snatched up in a matter
of 10 seconds to a point several miles away, and over 70,000
feet in the air!

$PMGNTRK,2145.789,N,15807.538,W,21084,M,220537.59,A,,280109*63

Four minutes later, I found myself whipped a few miles to a new,
still higher, position:

$PMGNTRK,2142.612,N,15804.135,W,21407,M,220959.11,A,,280109*6A

Then I was dropped almost straight down to near sea-level and
then back close to the point of original lift-off at great
speed:

$PMGNTRK,2142.155,N,15804.248,W,00047,M,221009.60,A,,280109*6F
$PMGNTRK,2141.974,N,15800.241,W,00043,M,221011.60,A,,280109*67

There were a couple brief similar episodes later, but not as high.

$PMGNTRK,2140.502,N,15809.925,W,00000,M,222843.62,A,,280109*62
$PMGNTRK,2140.501,N,15809.860,W,10275,M,222916.63,A,,280109*60
$PMGNTRK,2141.919,N,15808.917,W,10268,M,222918.62,A,,280109*67
$PMGNTRK,2141.790,N,15800.791,W,00030,M,222936.64,A,,280109*64

Traveling at these great speeds, I ended up with about a 120-
mile walk, where most people got by in less than six.

Oops! Here I go again!

$PMGNTRK,2146.424,N,15805.374,W,00135,M,223421.63,A,,280109*6C

$PMGNTRK,2146.891,N,15809.027,W,00000,M,223628.64,A,,280109*6C
$PMGNTRK,2141.835,N,15800.767,W,00001,M,223634.63,A,,280109*64

That was a long way to go in six seconds! And then I get whipped
right back out again:

$PMGNTRK,2144.034,N,15807.311,W,00001,M,224256.66,A,,280109*68
$PMGNTRK,2144.010,N,15807.261,W,09029,M,224311.65,A,,280109*6A

$PMGNTRK,2141.765,N,15800.957,W,00017,M,224520.65,A,,280109*63

$PMGNTRK,2134.920,N,15802.433,W,00000,M,225031.66,A,,280109*62

$PMGNTRK,2144.233,N,15803.924,W,00000,M,225146.65,A,,280109*64

After some back-and-forth like the above, I finally end up at
the right destination before 1 pm:

$PMGNTRK,2141.655,N,15801.059,W,00001,M,225248.66,A,,280109*6B

No UFO's were reported, and anyway, I'm sure I would remember
being snatched by one. But what other explanation? (Meanwhile,
I of course edited the log to show my intended hike.)

I used the same GPS on a hilly hike yesterday, and except for
briefly losing the satellites under heavy foliage, it tracked
me on the ground, on the trails. Along the beach, it was
tracking nine satellites just about every time I looked.

Bart Mathias