There are a LOT of sources via www.Matweb.com
& on that site you can look up an one of the dozens of varities of G10 so that you can order one which has the physical properties that you need. As there are a huge number of types of "G10", most with differing properties. Some being as strong or stronger than various grades of aluminum
, others being weaker, or having better electrical
insulative properties, etc.
Though for the most part, on boats, you don't need the super high end stuff. Or even G10 necessarily, vs. some similar sheet composite laminate. Just know that there are different types & grades, much as there are alloys of steel
, or aluminum