: Do you want to get the dirt and discoloration out of the cats by sanding
: them? Then would be cruel, as the cats would scratch the @#$#@ out of
: whoever was holding it.

: Seriously, though. The surface of wood slowly oxidizes and accumulates a
: layer of cells that have changed color. If your panels have been around
: for a while, or have been exposed to the sun for a while (UV speeds this
: process) then if you just spot sand you may encounter some local changes
: in wood color. You may want to lightly sand the ENTIRE panel to keep the
: color even.

: Depending on the size of the panel, this could be a lot of work, or maybe a
: waste of time. You may want to save the sanding until after the panels
: have been joined together, when you would be sanding them anyhow. Just
: make sure you don't embed a footprint under the glass tape and resin at
: the seams.

: Test a small area to see if the muddy areas can clear up. You might try using
: a (rubber) pencil eraser, or an art gum eraser, or lightly hand sand with
: some fine sandpaper (no power tools) to see if it helps.

: If the pawprints were very wet then the dirt might have been absorbed deeply
: into the wood. There are bleaches available to lighten such stains,(oxalic
: acid, household chlorine bleach, etc.) but it is hard to bleach just one
: irregular spot and make it match the surrounding area. If the sanding
: doesn't do the job you may want to use a stain to obscure the outlines of
: the pawprints and make them less noticeable.

: Start storing your wood with the good side down. Otherwise your cats may come
: back on another damp day and repeat the problem.

: PGJ
Or as an alternative, consider that the boat will be around long after the cats are gone. You might want to leave some of the prints as a reminder, after all you like them enough to let them in your shop, and they like you enough to inspect your work.
Bob