Mast Rot
I suggest you contact Catalina direct and talk to them about this problem and repair. Mast support rot can be very serious as the support forms part of the "compression sandwich" of the mast, stays/shrouds, and deck/keel holding the mast up. If you support/compression post are rotted for a foot or more than it's very extensive.The water could be coming down through the mast itself through cracks in the deck (on the C25 the mast is deck- stepped so there'd have to be a crack in the deck itself for water to penetrate). These may not be readily apparent as they could be under the deck step. It's also possible the water is coming up from below although it would be unusual, I would think, for water from below to penetrate up a foot into the post. So my bet would be a problem on the deck, which can also mean delamination, wetting and rot in the plywood deck core.This isn't an insurrmountable problem but has the potential to be serious in terms of the rig. Catalina has an excellent repair guide for the C30 on this type problem so I'm assuming they have a similar guide for the 25. Good luck!Mike TurnerS/V Amity (C30)