Base of mast is corroding

[dofthesea]

Help the base of my mast is corroding slightly and I can't figure out what the issue is. Any ideas? Small holes are forming at the base where the bottom of mast is in the aluminum mast boot. This is on an IF that is deck stepped.

Aloha

[TheOffice]

It is corrosion from moisture and a mast step that is a different metal. You may have to pull the mast, cut off the corroded metal and build up the step.