Off topic a little, but, I am going to stern mount my antenna this year, and move it up to top of mast next year. Just use VHF to open bridges. But, in the long run should be available for emergencies.
A much less elegant solution, but, would provide more options for drilling holes: have a cable exit at base of mast, and plug into deck mounted socket. This, however, is more prone to corrosion, leakage, and tripping hazard.