where to get foam for making custom bords?

Guys
I in Costa Rica the waves here are great but I can“t get foam to make custom bords #1 what is the best foam to use for "floating". #2 Where the hell do you get this xxxxx . Any advice is appreciated.
Pura Vida
Rudi
I in Costa Rica the waves here are great but I can“t get foam to make custom bords #1 what is the best foam to use for "floating". #2 Where the hell do you get this xxxxx . Any advice is appreciated.
Pura Vida
Rudi