This is a fairly common problem not unique to Hunters but the mast base is prone to water intrusion. The deck plate is flat and has at least one hole intended to drain water running down the mast. First, make sure that drain hole is clear and will allow any collected water to exit above deck. If thats not the problem, the other typical cause is water running down the internal wires which go straight into a collar through the deck and into the boat. This is the more likley source and unfortunatley, can't be fixed without stepping the mast to do one of two things:
1. carefully fill any void spaces between collar and wires with sealant (not usually effective), or
2. make a turn in all cables prior to entering the collar to promote water dropping off the cables before they pass through the deck plate.
It's usually fixed by simply clearing the drain hole above deck so no worries, yet.