Compression Post Leak

Someone recently asked, "So, you've fixed all of Kingsley's leaks?" 
I said, "Yep."
My wife said, "No you didn't, what about the compression post?"
I replied, "Oh, ya, well, I've fixed all of the leaks under the boat...not the top."

   Anyway, the picture above is where the compression post connects from the inside of the boat to the bottom of the mast. The compression post is in lieu of a mast that goes all the way through the boat. We were a little scared at first of purchasing a boat with one but if they are installed correctly they should do the job just fine, especially in protected waters...a.k.a. - our mast hasn't broken off yet!
   But, it's slightly leaking. I suspect water is entering at the very top of the mast and running all the way down into the boat (looks like we should hoist the cat up there to check it out). I think I'll just re-fill around the inside base with some silicone or epoxy...problem is, where will the water go when I seal it from below? Hmmm, might have to go aloft soon and figure it out.

You can see the old epoxy not doing its job (white stuff).