Currently there is fiberglass coating on it, with a decayed gelcoat (looks like ****). A couple bubbles here in and there in the fiberglass itself but overall very good structural condition. I have had one plaster company come out, and one fiberglass company come out. Fiberglass was a little more but offered a 15 year warranty vs. 3 for the plaster. Fiberglass company has been doing it for something like 25 years.
The pool was supposedly last done in the 80's and the fiberglass guy mentioned that was very early for a fiberglass coating so maybe there were some cracks or other issues with the pool that made them switch to fiberglass instead of plaster (this has me a little concerned about going back to plaster).
I tried some searching but the stuff I found was either really old or for new pool construction. What do you guys think? Plastering seems to be way more popular, maybe just because fiberglass is a little more expensive?