technical diving. Depth range The depth range applicable to scuba diving depends on the application and training. Entry-level divers are expected to limit themselves to about to . The major worldwide recreational diver certification agencies consider to be the limit for recreational diving. British and European agencies, including BSAC and SAA, recommend a maximum depth of Shallower limits are recommended for divers who are youthful, inexperienced, or who have not taken training for deep dives. Technical diving extends these depth limits through changes to training, equipment, and the gas mix used. The maximum depth considered safe is controversial and varies among agencies and instructors, however, there are programs that train divers for dives to . Professional diving usually limits the allowed planned decompression depending on the code of practice, operational directives, or statutory restrictions. Depth limits depend on the jurisdiction, and maximum depths allowed range from to more than , depending on the breathing gas used and the availability of a decompression chamber nearby or on site. Commercial diving using scuba is generally restricted for reasons of occupational health and safety. Surface supplied diving allows better control of the operation and eliminates or significantly reduces the risks of loss of breathing gas supply and losing the diver. Scientific and media diving applications may be exempted from commercial diving constraints, based on acceptable codes of practice and a self-regulatory system. Applications Scuba diving may be performed for a number of reasons, both personal and professional. Recreational diving is done purely for enjoyment and has a number of technical disciplines to increase interest underwater, such as cave diving, wreck diving, ice diving and deep diving. Underwater tourism is mostly done on scuba and the associated tour guiding must follow suit. Divers may be employed professionally to perform tasks underwater. Some of these tasks are suitable for scuba. There are divers who work, full or part-time, in the recreational diving community as instructors, assistant instructors, divemasters and dive guides. In some jurisdictions, the professional nature, with particular reference to responsibility for health and safety of the clients, of recreational diver instruction, dive leadership for reward and dive guiding is recognised and regulated by national legislation. Other specialist areas of scuba diving include military diving, with a long history of military frogmen in various roles. Their roles include direct combat, infiltration behind enemy lines, placing mines or using a manned torpedo, bomb disposal or