Practice on the beach! My kid (6) played with a couple friends on a boat last summer for hours swinging on the wire and jumping along the rail... he was "on it" after that. He loves to sail... as long as the boat has a trapeze! That "play" time was really effective. He has great balance out on the wire / water now. That is a good lesson for all of us. Practice a bunch on the beach. Don't wait for that good day and waste it "practicing" on the water.