Polyester Resin: This is the resin most commonly used for boat building today, and most boat owners are familiar with it. It is inexpensive and generally all-purpose. It has low stretch (elongation) properties so it is not used on modern high-performance boats, but it is perfectly adequate for most boats.
If your building a race boat, this is not for you. Despite what you made read on the internet Polyester Resin is a very good product and it is what most new boats are manufactured out of today (2019)