Portable chair

Gentleman,
As the years catch up, it is more of an inconvenience to sit down and
get back up when re-rigging. I find myself looking for a rock, clump
of high grass, log or little hill to sit on so I don't end up sitting
directly on the ground. Before I go to the lab and invent some type of
folding, adjustable, tripod chair I can carry along on my back, I was
hoping some of you older farts (I mean fishers)(no...anglers) may have
a portable device you use and might share with me (toilets are a bit
heavy to carry on my back...for any wise crackers whom I doubt there
are many on ROFF)
Most Sincerely,
Guy