Replacing foam in bass tracker???

Gutted all the wood/carpet out of my tracker today and found the foam sheets in the floor are in bad shape. I would like to replace but I haven't been able to find anything reasonably priced. Anyone got any ideas on what to use and where to get it?

Thanks for any help.

Try going to a builders supply store and look at the 4x8 sheets of foam.If you have a store close that services chicken houses they might have it up to 2 or 3 inches thick. We used to used styrofoam as insulation on scrubbers and glued it to the scrubbers with clear silicon.

Question-----would foam sheets add to stability of all aluminum boat.Less rocking side to side????????

Defoor Supply Co in Macon Ga. has 4' X 8' X 2" sheets, it is chemical resistant and will not absorb water, can't remember price seems it was $36. for 2 sheets