Foam fill the hull ?

[abl1111]

I was bored on this rainy Memorial Day - ' cats and dogs ' all day... So, I hooked up to the Seacraft website and read how the newer boats are foam filled... Got me thinking :

There are a few large areas under the water-line, i.e. under the large well between the helm and pass seats, that could be shot w/foam in my 23' Tsunami. Are there any benefits or drawbacks to this idea ?