This week I started sanding off 30 years of bottom paint on the Hunter36 1981. I am wondering if the boats had some type of barrier coat applied. The best I can tell is I have paint in this order: red, dark blue, white, then blue, then gel coat. The blue paint seems to be different than the others it is in really good shape and doesn't seem to have the divets like the other layers. Is this just because they sanded properly before applying the new (at that time new, bottom paint)???? The other layers have all of these divets. I am guessing it is because they had barnacles and they/PO/ contractor scraped them off and DID NOT sand. In other words they just rolled on the new bottom paint. Also, I started out using strippers to remove the paint. They didn't work all that great and wife really didn't like the smell. haha We did wear respirators. Now we are using 36 grit orbital sanders. Laborious but it works. Any thoughts?