I don't believe you can dry core by drilling holes. If it is wet cut and remove it. And of course cure the leak(s) that made it wet to start with. If the core is wet and you seal it in all it takes is warmth to promote rot in the near future. As well if you are far enough north for winter freezing the freeze/thaw cycles will possibly cause delamination if there is enough moisture present.
Living aboard in Victoria Harbour