BASE jumping is an activity that employs an initially packed parachute to jump from fixed objects. “B.A.S.E.” is an acronym that stands for four categories of fixed objects from which one can jump: buildings, antennas, spans (bridges), and earth (cliffs).
The acronym “B.A.S.E.” was coined by filmmaker Carl Boenish, his wife Jean Boenish, Phil Smith, and Phil Mayfield. Carl was the real catalyst behind modern BASE jumping, and in 1978, he filmed the first BASE jumps to be made using ram-air parachutes and the freefall tracking technique (from El Capitan, in Yosemite National Park). While BASE jumps had been made prior to that time, the El Capitan activity was the effective birth of what is now called BASE jumping. BASE jumping is significantly more dangerous than similar sports such as skydiving from aircraft, and is currently regarded by many as a fringe extreme sport or stunt.
BASE jumping grew out of skydiving. BASE jumps are generally made from much lower altitudes than skydives, and a BASE jump takes place close to the object serving as the jump platform. Because BASE jumps generally entail slower airspeeds than typical skydives (due to the limited altitude), a BASE jumper rarely achieves terminal velocity. 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.