I had a hull replaced late last fall and unfortunately i have only been out in it one time so far , it had been sitting in it's white bubble wrap untouched since last Nov.
I think it's normal to have a few inches of water inside the yak , my previous Outback usually had a few inches of water after a days fishing and so far the new one does as well (although only taken out once) .
I attribute it to the rudder line openings and rear hatch, i can't remember a single time where the inside was dry. I really wish water wasn't inside though, it's a major pita getting it out of there after every trip lol.
For the 1st 3 years I had a dry hull unless I was in very rough weather, then the fore hatch would leak a little that's it. It looks like the new ones have a heftier gasket. A few inches of water in the hull does not sound right.