: I've put a lot of minicell on the inside of my boats, but have never tried to
: affix any to the outside. I assume that that will work fine also (with
: some standard hydrogrip or similar product), but before I run sandpaper
: over the stretch of deck that I plan to attach it to, I'd like to get a
: more informed opinion.

Clean the deck well (I use lacquer thinner) and use contact cement. It will adhere just fine.

: FWIW, I find that the way I secure and remove my
: Greenland paddle while underway leads to a lot of superficial marring of
: my otherwise shiny gelcoat, and would rather have a few inches of thin
: minicell where the paddle end presses down against the hull, than
: scratched gelcoat.

Minicel is not the best material for this, unless you're using the "skin" side out (the harder black side - your material may not have this). It's not very abrasion resistant and it gouges/tears pretty easily. You'd be better off to use plastic tread tape to protect the deck. You can see examples in my "Deck Rigging" album (page 2) at the link below.