The large smooth tires work best, they must have the cradles. The boat needs to be be perfectly balanced before you start to move it. To much weight on the bow and you are lifting and pulling, to much weight on the stern and you have to pull down and pull forward. I can put the wheels under and move my nacra 6.0 by myself in South Florida sand and I am 62 years old. When you return to the beach and the wind is blowing onshore, I will leave my jib on to help move the boat.