My glider also has the GPS-NAV 20. Works well. At first, I used to
take it home at the end of each flight. That was not a big deal. The
unit is attached with velcro.

Later, I bought an iPAQ. Now, I download to the iPAQ, and then take
the iPAQ home.

Either way, you'll be taking something home.

Raul Boerner
LS6B - DM