will this system remove paint off hull and deck back to gelcoat without damage to fiberglass? thanks

thats probably your best bet. i hate to say it but sometimes its more work avoiding painting it than actually sanding/painting. if it is a good quality paint job it will not likely come off easy and the damage caused in removal is tuff to deal with. what boat is it? do you have any pics you can post?

improper sandblasting will hurt your paint. i would suggest media blasting. typically they will use plastic media, or walnut shell's, which are not going to harm the fiberglas or gell coat.

ooops, i meant will hurt your base= gel/ glass