s ▁the ▁ag ency - spec ified ▁limits ▁of ▁recre ational ▁div ing ▁for ▁non - prof essional ▁purposes . ▁Techn ical ▁div ing ▁may ▁expose ▁the ▁diver ▁to ▁ha z ards ▁beyond ▁those ▁normally ▁associated ▁with ▁recre ational ▁div ing , ▁and ▁to ▁greater ▁risk ▁of ▁serious ▁injury ▁or ▁death . ▁The ▁risk ▁may ▁be ▁reduced ▁by ▁appropriate ▁skills , ▁knowledge ▁and ▁experience , ▁and ▁by ▁using ▁suitable ▁equipment ▁and ▁procedures . ▁The ▁skills ▁may ▁be ▁developed ▁through ▁appropriate ▁special ised ▁training ▁and ▁experience . ▁The ▁equipment ▁often ▁involves ▁breath ing ▁g ases ▁other ▁than ▁air ▁or ▁standard ▁nit ro x ▁mi xt ures , ▁and ▁multiple ▁gas ▁sources . ▁ ▁The ▁term ▁technical ▁div ing ▁has ▁been ▁cred ited ▁to ▁Michael ▁M end uno , ▁who ▁was ▁editor ▁of ▁the ▁( now ▁def unct ) ▁div ing ▁magazine ▁aqu a Cor ps ▁Journal . ▁The ▁concept ▁and ▁term , ▁technical ▁div ing , ▁are ▁both ▁relatively ▁recent ▁advent s , ▁although ▁divers ▁have ▁been ▁eng aging ▁in ▁what ▁is ▁now ▁commonly ▁referred ▁to ▁as ▁technical ▁div ing ▁for ▁dec ades . ▁ ▁Origin ▁The ▁term ▁technical ▁div ing ▁can ▁be ▁trac ed ▁back ▁to ▁the ▁cover ▁story ▁of ▁the ▁first ▁issue ▁of ▁" A qua Cor ps " ▁magazine , ▁in ▁early ▁ 1 9 9 0 , ▁titled ▁call ▁it ▁" High - T ech " ▁D iving ▁by ▁Bill ▁Hamilton , ▁describing ▁the ▁current ▁state ▁of ▁recre ational ▁div ing ▁beyond ▁the ▁generally ▁accepted ▁limits , ▁such ▁as ,