Accessing Under Floor Leak

[Boogi_man]

I have a leak that I believe is originating at the fresh water tank. I have wood flooring and the undercarriage is enclosed with a single piece of corrugated cardboard-type material.

My question - What will I encounter when I pry up the flooring to access the leak? What is entailed in replacing the floor planking? It seems an easier route than slicing into the one piece underneath.

Thanks for the assistance!