I "upgraded" to an HO 4 person tube that i bought from Costco a few years ago. We are just now getting into using the boat again (rough last couple years) and took the family out to the lake for the day. Long story short is that this big tube is heavy and I'm assuming because of the drag in the water can't get it to swing. It wanted to track straight behind the boat between the wakes and not fall off of either side. Even if I give moderately sharp turns it still just stays in place. I had a sportsstuff rampage that would get a little squirrelly so my wife made me sell it and get this for the stability. Now my kids are getting older and want more thrill. I tow the tube with a two point harness (non pulley type) and a 50ft bungie rope. I thought the bungie rope would sling shot the tube around but it doesn't. Suggestions?