I use Polyurethane inside and out. Soap n water cleanup of brushes and hands too. Multiple light applications, available in several finishes Satin or Gloss.
I use this also when applying the light weight fibreglass cloth. Works well, virtually no odour.
I only glass the outside of the hull. Deck, and depending upon the vessel, say a sailboat , the fibreglass is placed on the outside of the deck structures which gives a water tight seal, generally 😄