How does the mast drain?

[Wdemeter]

How does the mast drain on the Y30? Now that I have sealed the partners with Spartite, it occurs to me that a lot of the water on the floor of the Head after a rain is coming from the inside of the mast. I poured water into a sheave opening above deck, and it was flowing out between the mast and exterior ring at the mast step. Is this the way it drains? I had always assumed it was draining to the bilge. I recall seeing this issue addressed in the old forum, but couldn't retrieve it from the archives.
Bill