well, i dont see why not, when planes ditch in the water at slow speed, they dont sink. its just like being on land, so it shouldnt be too difficult to recode aa couple things to drop supplis, for pt boats and cv groups, and to allow the pby to land and take off from the water...
But im not a programmer, so i dont know for sure.. oh, and there was a floatplane version of the A6m too...

But it would be really cool to see.