Vance your full of shit! 20,000? first jump No way... the air is very thin up that high. not much oxygen. you'll suffer from Hypoxia (lack of oxygen to the brain) also due thin air its harder to controll self in feel fall.. you fall faster than you do at 10,000 feet. first time stdent jumps are done at 3000 feet, tandem skydives between 10,000 and 13,000 feet depending on aircraft the single engine cessna pistons just won't climb fast above 10,000 the turbines (jets) will. I seriosly doubt your claim of a 20,000 feet jump I have thousand of skydives most at 13,500 feet a dozen or so at 18,000 feet and 5 at 23,000 feet and those were special skydives on oxygen all way up and bailout bottles (pony bottles) oxygen once you go above 15,000 your asking for trouble if your not trained and KNOW what your doing!