New structure for fiberglass floor

Hi guys, i'm sorry for my not so good english, i'm italian!
I need a help for the new floor structure of my boat: i bought a used boat and now i'm restructuring it.
under the floor panel the old structure was like this:

I cut and removed the central beam (the wood inside was rotten) and those 4 sleepers (the entire structure was soaked in water and so f*****g heavy).

now i have the "naked" hull and i have to design a new structure (lighter than the old one), my idea was like this:

with a 210cm long central beam and 5 of those transversal panels (i drew only one edge of them) but i don't know the materials, their thickness and if it's a good idea, can anyone help me?
thanks a lot!

 

My old boat, a "Winner" (brand name) has a fibre glass layup-insert that looks like an egg carton of various sized pyramids all joined together. No wood stringers to rot. Great idea but not for one-off or homebuilders.

Metal and FG panels have little stiffness so most any edge or V type laminated onto the flat surfaces will add stiffness. Some larger reinforcement and many small is probably best. Don't know how heavy or big the stiffeners should be. If you go too light and weak you may be making some repairs. That's how I did it w my plywood boat. Added panels where I thought there was too much flexing.

Your boat looks like it has a very concave bottom. I like the gunwale cap and coaming. Looks better than my boat. What you've drawn up looks good to me but I'm no NA.

 

i'm glad to give you a nice project for yours. however thanks for information, as soon as possible i'll post the work in progress photos!