Online Metals oddly has one of the nicest plastics surveys I’ve seen. I keep bugging them to carry G-10, but not yet. They do have a GPO 3 which sounds similar to G-10.. I will have to get some and see.
http://www.onlinemetals.com/productguides/plasticguide.cfm
I used and have been around GPO-3 and sometimes I used consumer kitchen cutting board in some applications. I can’t tell if used outdors under UV will last. It is heavy for a plastic. There are some plastics that resist both heat and corosion (oil and caustic) similar in weight to GPO-3 again UV unknown.
If you are looking for hull material the best I’ve seen and used was in Pelikan Kayaks. I threw that sucker down ravines, rocks, towed it sand with very limited scratche or dents and it sat in the sun on the deck.
“Proper” G10 is an epoxy based laminate. If the GPO is red its probably a phenolic resin laminate (although they say its polyester but then it would not have the temp properties they say). Either way they are just as good as each other as a reinforcement in composite boats unless you are a stickler for like resins. Peter