We just purchased our first pontoon boat ever. It is a 2008 Sweetwater 2586re by Godfrey Marine. Ours has 3 pontoons (a tri-toon I think you call it?). On the 2 outside pontoons, there is a valve, or nob about halfway down the pontoon, on the top. I was told these are for a pressure test to see if the pontoons are air tight, or water tight. But I don't see any drain holes/plugs in the back of any of the pontoons?? Could you please tell me how you would get water out of your pontoons if water does get in, if you have no drain plugs? Thanks!