Originally Posted by markpierce
Once a year. Every second year have the bottom repainted (two coats) and all 11 zincs replaced. Alternate years for inspection and any needed repair such as replacing any fast-disappearing zincs, treating the propeller for barnacles, etcetera.
How massive are your zincs?
I probably replace my zincs more often than necessary; but I only have two (rudder and prop nut) and they are inexpensive and very easy to replace while I'm diving under the boat. The prop nut zinc is for a 1.25" shaft and the rudder zinc is 3-3/4" diameter.
I'm amazed at how quickly the growth accumulates here in the warm Florida waters. Nothing a monthly dive can't clean-up.