Originally Posted by Minnewaska
Depends. If the new paint is compatible with the old, you only need to take it down to that which is still adhered well. Safe is to take it to whatever epoxy barrier coat may have been applied, unless that is letting go to.
If you have old bottom paint on your hull, is it still effective anti foul? Or could all the anti foul additives be leached out? Wondering if there is some benefit to leave the well attached paint on.