Is your boat in the water for prolonged periods or is it drysailed??
If it is in the water for prolonged periods, sure, you should not only have a bottom paint, but also a barrier coat. If it is freshwater, a good combination is Interlux 2000/2001 (the barrier coat--protects against osmotic damage--blisters) and VC17 (a bottom paint--Interlux product--good for freshwater--gives a smooth finish with teflon--to keep your boat fast--also dries very quickly after painting it on). I sail in Lake Michigan, and this seems to be a very popular combination.
Are you sailing in the Great Lakes or a completely closed body of water? If you are in a body with no growth other than slime a biocide might be overkill. I sail on the Columbia river and except for slime which comes off when I go out I have no problems. An occasional scrubbing is all that is necessary and I feel good about not indroducing additional chemicals in the water.