You lost me there.
I have a diver clean the bottom about twice a year--I have to have him come out and do my max prop zinc anyway. My knot log transducer is forever getting fouled. I painted my bottom a year and a half ago, before that it was 5 years and still looked good. I use Bryan at Northwest Diving, he's a very nice guy, reasonable and he can totally disassemble my Maxprop under water if needed.