Fast mold, not very expensive ( stich and glue foam? ?)

Hi to all,
I was thinking to some way to have a male model for making a mold for a boat.
it seems to me that two main aspect may be evaluated, one the work needed to have a smooth surface and then the cost of the tecnology used,
now it seems to me that the more expensive way is from large block of foam cut using big cnc machine.
now let's immagine to have a common small 3d cnc machine wich should work with panel with a max heigt of ( for example) 0,15 meters.
so i would buid up an hard chine version of my model for example in plywood, then gluing over it some quite flat piece of foam cnc cut
note that in that case i should be advataged by the fact that some partof the boat, for example sides or bottom may be of a developaple flat shape .
here i post a sample immage of wath i was thinking about
What's your opinion? does exist any similar experience?
Best regard

 

Looks doable. If you have a warm dry shop, cheap and easy-to-work alternative for ply is plasterboard. It's also easier to fair with filler..
Reckon you do the mold upside down, so it's simple to make a rigid jig.

 

thank you teddy for opinion
yes i agree may be plasterboard will result also cheaper ...