Although it is not in the temper to make seams in inflatable boats of a type of PVC because it is very common to have this problem, and states

the expiration date of the vessel (open all of the seams slowly because polymerized adhesives over time, but also from the heat).This ship is the exception, because the damage came from excessive bloating of the air space from the owner . We're stuck with the exposure and strengthened with a tape over the seam. Finally we got stuck a couple of PVC aid in the 2 front crosses(where they intersect the fabrics of the vessel.