This procedure has attracted controversy due to claims that it could potentially alter the natural behaviour of sharks in the vicinity of swimmers.
Similar cages are also used as a protective measure for divers working in waters where potentially dangerous shark species are present.
[3] Australian recreational diver and shark-attack survivor Rodney Fox helped develop a shark-observation cage in the late 1960s.
[5] Filmmaker Peter Gimbel was involved in the design of a shark-proof cage for the production of Blue Water, White Death (1971).
[9] The patent abstract details a self-propelled cage with at least one access opening and a mounting frame that carries both an air motor and a propeller.
The government considers the activity to be one of South Australia's "iconic nature-based tourism experiences", which supports 70 jobs and contributes over $11 million to the state's economy.
[22][23] The shark circled the boat several times, and began to attack the side of the cage, then started to crush and bite through.
Currie quickly swam out of the top of the cage and was pulled to safety by the boat's captain, who fended off the shark with blows to its head.
[24] Another incident reported in 2016 occurred off the coast of Mexico, when a shark that lunged for the bait broke into the cage and the diver was able to escape uninjured.