Well, I didn't make it through the season before my cart broke. I had to fix it so that I could go paddle. Here is a picture of the new and improved version. I was able to reuse some of the old parts, and the new wheels make a lot more sense. They don't weigh as much, they don't need to be inflated, and they don't take up as much space. I simplified the design a little as well. The first test run today, worked out real nice.
Here are some pictures from my paddle today.