IN that scale the barnicles can be replicated with sand or talus from a train supply, put some on a cutty block and either rool a pin over it or hit with a small hammer to crush smaller.. There is no correct or hight buildup area on a boat, they get everywhere except the propeller in most cased if the vessels moves at least once per week or so, the young villerges (SIC) cannot hand on good with their bissle threads