: but loes has the minwax helmsman spar polyurethane for 10/qt. does this work,
: or is varnish better?

Same difference, I think. PU is maybe a little tougher

: what does SPAR mean?

It's for spars (wooden masts and booms on sailboats), which implies a wet environment and lots of UV exposure. Better UV protection than regular varnishes. Most of them still say on the can "not for use below the waterline", but this is for vessels that live in the water. It's fine for our kayaks that spend maybe 5% of their lives (max!) in the water.

Shawn