Actually there is another way, other than the wing sockets, for rain water to get into the hulls. The end cap casting attachment points (four of them) for the cross beams. That is, where the cast aluminum cross beam end affixes to the hull. It is held into place by 3 screws, but also has a couple of guide pins along the bottom of the casting to help hold it into place and it is these guide pin holes that can leak. I know because one of mine did. To check, take off the crossbeams. Then with the hulls upright pour water to fill the depressions left where the cross beams normally go. Check in 30 minutes to an hour. If the water is still there, no leak. If the water has disappeared then that is a leak source (cause there may be others). Good luck