Thoughts about bottom paints for speed
A faster, harder bottom paint will make a difference in speed-- up to a point. That point being, when the bottom clogs up with slime and goo. Many hard-shell racing paints, like Baltoplate and VC-17, are less adequate in serious antifouling properties. I do not know your area; but in colder water like the Great Lakes you may have less problem with green slime than many of us do; so this may not be as much of a factor.
In my opinion ablative paints are the best compromise all around. They are easy to apply. They can be applied over just about anything. They require very little surface prep season to season. And because they wear away slowly (rather like seashore house paint), they may actually enable better speed, both because they do not allow slime buildup and because, by wearing away in the passing water, they ensure a pretty good state of laminar flow (they smooth out their own lumps and imperfections after a while).
However, a caveat-- as much as we all like to sit in armchairs discussing theory, the reality is that we may be talking about only a third of a knot or less. All depends on the conditions in which you sail, the weather of the day, boat loading, sail trim, sail condition, and about a hundred more factors that have nothing to do with bottom paint. One guy sailing an H34 with lumpy Pettit Trinidad may outsail even a more experienced guy with another H34 wearing polished VC-17, merely because his sheetline isn't as old and stretched-out or his crew needs less of a diet.
In my experience I know of no panacea to guarantee more speed under all conditions by way of installing better equipment or using better bottom paint. Unless you race very competitively and your boat is otherwise very tricked-out for racing, a switch of bottom paint may not result in much change, as far as you'll be able to tell. Since you say you went three years without changing or applying paint, I would presume this is not the case.
(One more theoretical point-- if you are serious about racing competively, consider the weight of two gallons of bottom paint on the boat. It's like having two gallon cans sitting in the cabin. So in theory the fastest thing would be the least quantity of bottom paint possible. This is why airlines don't paint their airplanes any more.)
Without a doubt your going to a folding prop is a very good first step. Mind that some race clubs penalize it though.
The thing I like most about Baltoplate is the color. It just looks cooler. If I could get it, I would have old-school 'racing bronze' (which, by the way, along with red was noted for carrying the highest copper-antifouling content amongst all colors-- and can be polished too).
I am putting Interlux ACT on Diana this year because of the reasons I gave for using ablative paints. I chose Shark White because I like the color (goes with the bootstripe and hull graphic).
