I've never heard of any tears in the hull along the seat, unless someone had been sitting in the seat, possibly playing around (rocking back and forth or side to side) while the PA was out of the water and sitting on a hard surface, like on a concrete floor in a garage...And I'm not saying that this is the case with your PA..
..I'm only using that one example of how a PA may be damaged in the way you described... Uneven force distribution against the hull
. In other words...Too much downward force focused in a small area when on dry land, comapred to a more spread out force through the entire hull (even force distribution) when in the water...Thats my theory anyway...
Check with your dealer. Maybe it is something that Hobie will repair for free, being that your PA is not that old. Good luck