Water may not be coming entirely from the mast. Inspected my as yet uncovered boat on the hard yesterday after a heavy rainstorm. Large puddle, about two pints, on the cabin sole just in front of the companionway ladder. That rain water aided by the wind from forward came in under the forward end of the companionway sliding hatch. That rain water opening has been troubling this boat for forty years. Presently I am replacing the cabin sole due to failure of the original plywood in that exact same area. Sometimes over the winter the boat yards have placed the boat on stands with the bow raised up slightly. That causes all rain falling on the deck ahead of the companionway sliding hatch to enter the boat by the described route and eventually fill the bilge. Waiting for the yard to shrink wrap which will end that problem for the winter. I believe most boats suffer from this problem.