Water trapped between hull and ski locker subfloor

[jmvotto]

Do you mean the drain in the locker going to the rear of the boat? If the drain to the rear is broken, cracked or disconnected that may be the problem. It is still is a lot of water getting under the locker.

yes the drain hole, water could get from the bildge area as well from fast stops etc. down hill trailering or just sloshing rollers over the bow around in the locker.