I guess I pumped a little too much air into my sevylor rio inflatable. It's one of these: http://images.shipstore.com/ss/images/SEV/SEVKCC305.JPG The sun was very strong, and as all well-educated suba divers know, if you double the temperature of a gas, you double the pressure (Boile's Law) --- long story short, the air heated up and expanded inside an air-chamber and it started making a hissing noise from somewhere it shouldn't have been --- sure enough, when I looked there was a two or three millimeter-long split right next to a seam that was venting air at a goodly rate. When I bought this sevylor it was used and I forgot to bring the patch kit and I don't know if I can still get the patch kit or not. Probably not, but I'm still trying, maybe I still can. From looking at the blue, plastic-like material from which the leaking air-chamber is fabricated, I don't think it's the same as bicycle inner-tube material so standard inner tube patch kits won't work (or will they?). Anyone have any ideas about patching this bad boy? The affected air-chamber is the starboard bouyancy cylinder, not the single, structural rigidity chamber on the bottom that resembles a narrow air mattress. The split is near the bow, halfway up, on the inside right next to a three or four millimeter high ridge formed when two edges were joined (the seam), so unfortunately the surface next to the leak is not flat. I tried a field repair with duct-tape but because of the protruding ridge of the seam, it didn't work properly and I had to forget about paddling, sigh. Thankfully this didn't happen just prior to my last major three day trip around Pitt Lake!