Re the origins and motivations, Wikipedia says this:
Technical diving emerged in between the mid-1980s to the mid-to-late-1990s, and much of the history of its development was recorded in "aquaCorps, The Journal for Technical Diving" (1990-1996), started by Michael Menduno to provide a forum for these aspects of diving that most recreational diving magazines of the time refused to cover.
At the time, amateur scuba divers were exploring the physiological limits of air diving while exploring the diving environment, and looked for ways to extend those limits and for way to extend breathing gas supplies as they went deeper and stayed down longer. The military and commercial-diving communities had large budgets, extensive infrastructure and controlled diving operations, but the amateur diving community had a more trial and error approach to the use of mixed gas and rebreathers. Consequently a relatively large number of fatal incidents occurred during the early years, before a reasonably reliable set of operating procedures and standards began to emerge, making the movement somewhat controversial, both with the mainstream diving establishment, and between sectors of the technical diving community.[
While the motivation to extend the depth and duration range by military and commercial divers was mainly driven by operational needs to get the job done, the motivation to extend recreational diving depth and endurance range was more driven by the urge to explore otherwise inaccessible places, which could not at the time be reached by any other means.
The urge to go where no one has gone before has always been a driving force for explorers, and the 1980s was a time of intense exploration by the cave-diving community, some of whom were doing relatively long air dives in the 60-125 m depth range, and doing decompression on oxygen. The details of many of these dives were not disclosed by the divers as these dives were considered experimental and dangerous, not for the ordinary person, but necessary to extend the frontiers of exploration, and there were no consensus guidelines for scuba diving beyond 40 m.
Origin
The popular use of the term technical diving can be traced back to the cover story of the first issue of "aquaCorps" magazine (1991 through 1995), in early 1990, titled call it "High-Tech" Diving by Bill Hamilton, describing the current state of recreational diving beyond the generally accepted limits, such as, deep, decompression and mixed gas diving. By mid-1991, the magazine was using the term technical diving, as an analogy with the established term technical (rock) climbing. More recently, recognising that the term was already in use by Royal Navy for rebreather diving, Hamilton redefined technical diving as diving with more than one breathing gas or with a rebreather. Richard Pyle (1999) defined a technical diver as "anyone who routinely conducts dives with staged stops during an ascent as suggested by a given decompression algorithm". The term technical diving was also used in the US as far back as 1977 by the California Advisory Committee on Scientific and Technical Diving (CACSTD), to distinguish more complex modes of recreational diving from scientific diving for regulatory purposes. In the US the Occupational Safety and Health Administration categorises diving which is not occupational as recreational diving for purposes of exemption from regulation. This is also the case in some other countries, including South Africa.Technical diving emerged in between the mid-1980s to the mid-to-late-1990s, and much of the history of its development was recorded in "aquaCorps, The Journal for Technical Diving" (1990-1996), started by Michael Menduno to provide a forum for these aspects of diving that most recreational diving magazines of the time refused to cover.
At the time, amateur scuba divers were exploring the physiological limits of air diving while exploring the diving environment, and looked for ways to extend those limits and for way to extend breathing gas supplies as they went deeper and stayed down longer. The military and commercial-diving communities had large budgets, extensive infrastructure and controlled diving operations, but the amateur diving community had a more trial and error approach to the use of mixed gas and rebreathers. Consequently a relatively large number of fatal incidents occurred during the early years, before a reasonably reliable set of operating procedures and standards began to emerge, making the movement somewhat controversial, both with the mainstream diving establishment, and between sectors of the technical diving community.[
While the motivation to extend the depth and duration range by military and commercial divers was mainly driven by operational needs to get the job done, the motivation to extend recreational diving depth and endurance range was more driven by the urge to explore otherwise inaccessible places, which could not at the time be reached by any other means.
The urge to go where no one has gone before has always been a driving force for explorers, and the 1980s was a time of intense exploration by the cave-diving community, some of whom were doing relatively long air dives in the 60-125 m depth range, and doing decompression on oxygen. The details of many of these dives were not disclosed by the divers as these dives were considered experimental and dangerous, not for the ordinary person, but necessary to extend the frontiers of exploration, and there were no consensus guidelines for scuba diving beyond 40 m.
