Wiring
It may be useful for you to know that my boat, a 1980 model, came with the set-up you are thinking of doing, but with no little access port in the mast. The connectors are at the bottom of the mast, but inside it, and the wires go through the holes straight down into the compression post. The hole is sealed with some sort of goop, probably silicone or equivalent. There is a hole almost at the base of the post, from which the wires emerge. They run along the top part of the port side of the bilge, and then pass into the aft locker under the port side settee. They then go through a conduit under the ice-box, under the stove and into the forward locker under the quarter berth, where the electrical distribution panel is located. There has never been any leak from the mast down into the compression post, nor from the compression post into the bilge. If I were doing the job from scratch, I would line the inside of the new hole with epoxy, the better to prevent any ingress of water into the deck core. I would be reluctant to cut too big a hole in the mast side, for structural reasons. It is true that I cannot disconnect wiring unless the mast is raised a few inches, but this has not been a big encumbrance. And, I have enough wires in the mast for different things, to have had to install a SECOND conduit!I have a question to you, however. My compression post is based in a hunk of fiberglass, or possibly fiberglass encased wood. This cube is about four inches high anad spans the bilge. Just above where the mast emerges from this base, and right where the exit hole for the wires is, there is a spot where corrosion of some sort has eaten away a hole about an inch in diameter. This has been going on for about eight years. There does not seem to be any stray current, and everything is dry. Every now and again, I clean the area of the aluminum powder. But it continues, very very slowly. I disconnected the lightning ground, thinking that I was suffering from dissimilar metals augmented by stray RF current flowing up the lightning ground which was connected to the keel which is my HF radio ground-plane. Nothing changed.I can see how at some point I might have to sleeve a section of the post, perhaps three to four inches high. Which gets to my question. How did you remove your compression post? Is yours also based in the same type of block mine is? Did you cut it away, or what? Any thoughts on this? My email address is: tims@cabomarina.com.mxGood luck on your wiring. I think it will be a piece of cake. Remember, the deck between the post and the mast is supported by the compression between the two.