No. But it helps. The fitter you are the easier you will be able to deal with the rigors of being a PADI Scuba Diving Instructor. This industry will require you to carry scuba tanks, move scuba equipment and help in a variety of ways around shops and boats. Adding to this, diving is a physical sport, it places stresses on your body and cardiovascular systems, so it’s best these are in good shape before you become an industry pro!