I thought it was already banned. The Berkeley Wednesday night ski league banned it a while ago. I have never seen one, but I think you should have to use something like that in a special division. You have all probably seen the amputees that get carbon fiber lower legs and can sprint and jump much better than before. As for jump slings, the jump event is athlete against jump, in my opinion. 6/30/2010 OWSA Open Lake - Glass City - 1 (10M129) Water Ski with our club behind competition boats and experienced skiers. All ability LVL from 2 ski beginners through beginner slalom course skiers. Liberty Center, OH YES  6/30/2010 NorCal MasterCraft Wed. Night Ski League - 5 (10W191) Handicap based scoring for nightly and season end prizes. The PowerVest is banned from this competition. Berkeley, CA YES  6/30/2010 Lowe Down Wed Nite 1 (10S091) 2 Pulls PandC,   Slalom  2C , Trick  1C , Jump  2C Hillsboro, TN