Do you have divers available where you are? I get my hull scrubbed by one of my customers on an as need bases or do it my self. At that time, the hull, zincs, transducers, through hulls, rudder, prop, and shaft are inspected and taken care of as necessary. If a diver isn't available in your area, every 6 months would seem prudent and reasonable to me.I'm just looking for opinions. I'm having the bottom job on Hattini this week and wondering the validity of doing a quick haul and pressure wash every six months.