What is this hole in the floor?

[Callmesince]

I would leave it accessible we are framing around it and making the floor be able to pop up over it. If you cover it the only way to access is to take out your fuel tank!

 

[gs1949]

I intend to leave mine easily accessible too. When I tore up the floor I could tell nobody had opened that area up since the bus left the factory in Georgia in 1995. I could tell this because the hole was covered with an approximately 6 inch square steel patch, originally painted aluminum grey, but by the time I saw it now slightly rusty. Underneath the patch was just the ugly green MLV flooring, intact, over a big hole in the plywood. If anyone needed access to the tank, they would have cut the vinyl.

Since nothing has been done in the fuel tank since 1995, I think it would be best if I planned ahead and kept things as simple as possible. Just my 2 cents worth. Interesting thread, thanks to all the posters.