I never varnished for the first couple years I built boats, was way too impatient to getter on the water!

You can see the UV damage as it slowly appears, no big deal. And it's no big deal to fix it either. Just sand where it whitened, and reapply epoxy is all I ever had to do. I finally got tired of reapplying epoxy so often and coaxed myself to start using varnish, and reduced the R&R's from once every several weeks to once or twice a year. That's here on the Texas Gulf Coast near Galveston.

I'm in the process of R&R'ing an old veteran from those days right now: my good old Squeedunk Cormorant hybrid from 2003. Yes, boats can survive that sort of treatment, all four of mine from back then have.