Floor soft and flexes

[phatdaddy]

If the bottom is already compromised, why not cut it out? Leave a lip along edges to support the new bottom. Encapsulate a new core in fiberglass and bond to the top of the lip

[SkunkBoat]

I don't think screws are going to last. The core under the glass is shot, thats why it flexes.
Without making a project out of it, instead of replacing the core, I would say to bond a new core on top. Its not a large area and you don't seem intent on a permanent "pretty" fix.

That could be as simple as silicone and a piece of pvc board or plywood. You need to spread the forces with a bond of the board to the existing glass.

[steplift20]

I cut a piece of plywood and it fits nice,covers it good I know the right way is doing what phatdaddy said but it's not a floor that is always stood on so what I think I'm going to do is glue it down with a adhesive caulk , paint it and that should be good p.s. I did get fiberglass to fix a crack the is on the side of the floor so after I fix that I should be good, I hope

[steplift20]

Hey guys thanks for the advice, what it did today I had a crack in the cabin by the floor so I fiberglass it and I think it's going to be stronger as for the floor ,I have a piece of marine ply wood and cut it yo size and I'm going to glue it down and paint it That should be good I hope it is a small area but I had to address it thanks again guys