I am installing radar on my 1989 Hunter 33.5. I had the mast pulled last fall mounted the antenna and ran the radar cable down the mast. What I have not figured out yet is how to get the cable through the mast base and back to the display at the helm. The current mast wiring goes through the mast base and is sealed with some kind of cast material that fills the whole base. What is this stuff? Can I just drill through it and reseal after running the cable? From there I am hoping I can remove trim around the compression post or lift the cabin sole to ease running the cable through the boat. Any advice on running this cable is appreciated. I am familiar with basic wiring and the use of fish tape.