50' is a piece of cake. I jumped 80' one time, broke my tail bone, a minor injury which caused discomfort for a week or so. I was attempting to determine the optimum altitude from which to cut away a parachute and fall into water with maximum crowd appeal and minimum pain. I settled on 50'. The jump was part of a halftime show at a concert at a waterfront resort. It all came off well, but next time I need to check the depth of the water more carefully.