Base jumping

BASE jumping grew out of skydiving. BASE jumps are generally made from much lower altitudes than skydives, and a BASE jump takes place in close proximity to the object serving as the jump platform. Because BASE jumps generally entail slower airspeeds than typical skydives, because of the limited altitude, a BASE jumper rarely achieves terminal velocity (that speed achieved after twelve seconds of acceleration). Because higher airspeeds enable jumpers more aerodynamic control of their bodies, as well as more positive and quick parachute openings, the longer the delay, the better.
Skydivers use the air flow to stabilize their position, allowing the parachute to deploy cleanly. BASE jumpers, falling at lower speeds, have less aerodynamic control, and may tumble. The attitude of the body at the moment of jumping determines the stability of flight in the first few seconds, before sufficient airspeed has built up to enable aerodynamic stability. On low BASE jumps, parachute deployment takes place during this early phase of flight, so if a poor "exit" leads into a tumble, the jumper may not be able to correct this before the opening. If the parachute is deployed while the jumper is tumbling, there is a high risk of entanglement or malfunction. The jumper may also not be facing the right direction. Such an off-heading opening is not a problem in skydiving, but off-heading opening that results in object strike has caused serious injuries and deaths in BASE jumping.