We purchased our 1985 Catalina 25 last year. When we hauled last year we noticed many small bumps on the bottom. They went away after about four weeks on the cradle. When we hauled again this year they are back. They do not appear to be blisters but are hard bumps about one eighth inch in diameter covering about 70% of the underside. The hull was power washed when hauled. We use VC17 as an antifoulant. The hull at the waterline & below seems to have been coated by a previous owner. We cannot confirm what this coating might be. Does it sound as if this coating is absorbing moisture causing this rash? Is this a cause for concern? Other than this the boat is in great shape and was an excellent choice for our first sailboat. Dennis