Anyone have an opinion on using two or one part polyurethane paint for application on hulls above the waterline?

The original catamaran hull is manufactured from Nomex, a heat cured combination of honeycomb and pre-impregnated epoxy sheets. It never had a gel coat finish applied.

Now the original polyurethane finish is old and worn.

Is it better to use two or one part polyurethane on this hull, to bring it back to "Bristol"???

What are the advantages and disadvantages of both???

Any thoughts??

Tom