Deck vs. Keel Stepped Masts
Our boat (1985)has a keel stepped mast that is wet if there is a quart of water in the bilge.
We bought it last year and I had to trim 1/8 inch from the bottom to square it off. I also cleaned up the corrosion and sealed with 2 part epoxy paint.
When the mast was stepped last spring, the paint at the base was scratched...resulting in some additional corrosion this season, although nothing like before. Looks like we will be pulling the mast at a minimum of every other year.
If you decide to go with a keel stepped mast, try to get one that is spaced up a bit and easier to keep dry.