Found wet core is it too late?

[SSBN506]

Found wet core is it too late?

I am in them process of installing a holding tank in my boat. I drilled the hole for the pump out and was horrified to find the plywood was wet. It hadn’t rotted as far as I can tell. I let the plug I had drilled out dry and the plywood seemed to be fine. It isn’t brittle or soft.
My boat is a 1977 challenger 7.4 (25ft) with no soft spots I have found by walking on the boat. It had been surveyed two years ago and they did find two spots with elevated moister. One of them was where I drilled the hole.
My question is what I can do if anything to prevent it from getting really bad. I have a few ideas where the water could be getting in but am afraid if I seal them now I will cut of the air and rotting with start. My boat was covered over the winter so I assume the water has been in there for at least a year.

[JimsCAL]

Definitely find out where the water is getting in and deal with that. If the core isn't rotted, dry it out and you should be fine. Let this go and you will have a major jon your hands.

[SSBN506]

How do I dry it out? I have left the hole I drilled open for now is that the best way?