I have an Achilles SD-124. Recently I have been having issues with the keel completely deflating after about 20 minutes. While garaged the keel remains inflated to pressure, however as soon as it's put in the water it losses pressure. I have troubleshot as much as I can. After removing the floor boards and checking extensively for Ieaks I cannot find anything. I have also filled the bottom of the boat with water and applied as much pressure to the keel tube as I can with no results. The valve also appears in good shape. Anyone else have any similar issues? I'm wondering if the weight of people in the boat on the floor boards may have something do with it but it seems unlikely.