Thompson 240 Water under floor

[Last One]

I have 8" hand hole by my live well, Looks like a spray foam tube, there is water on the bottom. In front of the motor you have the gas tank, I am told this is a sealed compartment. Behind that are is where I think there is water.

I do not want just start cutting hand hole, wires boat supports and things. Thompson went out of business in 2001. Any one out there know a safe place to access the water. Ideally I would like to put a bilge pump in.