even though inexperienced jumpers often take part on tracking dives, the risks of such dives should not be underestimated. an efficient track can reach horizontal speeds of nearly 100 mph (one experienced diver was witnessed to keep pace with a twin-engine plane as it took off from deland municipal airport in 1995 thus registering his speed in excess of 115mph). collisions with other groups or with members of one's own group would result in serious injury or death. for this reason the number of inexperienced jumpers on a tracking dive should be limited by the organizer.