Catalina knows how to build boats, but doesn’t always build them well.
Your track was through bolted to a balsa cored
deck. If your track was leaking
water into the
cabin, it was also leaking water into the balsa
core. The wet balsa
core has rotted and crumbled to the point that you can not find it any longer.
This damage has surely spread well outside the area of the track, and REQUIRES a major
repair of the
deck structure. A
surveyor or
fiberglass repair tech can identify the damaged area for you.
Do not just fill the area under the track without fixing the rest of the water damage!
Sorry for the bad news.