BASE jumping is the recreational sport of jumping from fixed objects, using a parachute to descend safely to the ground. "BASE" is an acronym that stands for four categories of fixed objects from which one can jump: buildings, antenna (referring to radio masts), spans (bridges), and earth (cliffs). Participants exit from a fixed object such as a cliff, and after an optional freefall delay, deploy a parachute to slow their descent and land. A popular form of BASE jumping is wingsuit BASE jumping.
In contrast to other forms of parachuting, such as skydiving from airplanes, BASE jumps are performed from fixed objects which are generally at much lower altitudes, and BASE jumpers only carry one parachute. BASE jumping is significantly more hazardous than other forms of parachuting, and is widely considered to be one of the most dangerous extreme sports.
Fausto Veranzio is widely believed to have been the first person to build and test a parachute, by jumping from St Mark's Campanile in Venice in 1617 when over sixty-five years old. However, these and other sporadic incidents were one-time experiments, not the actual systematic pursuit of a new form of parachuting.
The acronym "B.A.S.E." (now more commonly "BASE") was coined by filmmaker Carl Boenish, his wife Jean Boenish, Phil Smith, and Phil Mayfield. Carl Boenish was the catalyst behind modern BASE jumping, and in 1978, he filmed the first BASE jumps which were 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.
After 1978, the filmed jumps from El Capitan were repeated, not as an actual publicity exercise or as a movie stunt, but as a true recreational activity. It was this that popularized BASE jumping more widely among parachutists. Carl Boenish continued to publish films and informational magazines on BASE jumping until his death in 1984 after a BASE jump off the Troll Wall. By this time, the concept had spread among skydivers worldwide, with hundreds of participants making fixed-object jumps.
During the early eighties, nearly all BASE jumps were made using standard skydiving equipment, including two parachutes, and deployment components. Later on, specialized equipment and techniques were developed specifically for the unique needs of BASE jumping.