I normally prefer the unlimited quantity of air that a pump provides. But last week I got a flat in the heaviest downpoor I have ever experienced. I was standing in 8 inches of water by the roadside with, literally, a waterfall running off the front of my helmet. My Roadmorph pump was so filled with water that it stopped working. I got the tire inflated to ~15 pounds and that was it. By that point, so many branches rocks and other debris had washed onto the road and with so little pressure, my tire pinch flatted in about 5 minutes. It was still relentlessly downpouring and my cell phone died too. I was so completely abandoned with my water-logged pump, I just rode the remaining 6 miles home on the rim. Fortunately I was riding my beater. CO2 would have saved me.