▁gas , ▁monitor ▁divers ▁during ▁long ▁decom pression ▁stops , ▁and ▁provide ▁communic ations ▁services ▁between ▁the ▁surface ▁team ▁and ▁the ▁expedition ▁divers . ▁In ▁an ▁emer gency , ▁the ▁support ▁team ▁would ▁provide ▁rescue ▁and ▁if ▁necessary ▁search ▁and ▁recovery ▁assistance . ▁ ▁Training ▁ ▁Techn ical ▁div ing ▁requires ▁special ised ▁equipment ▁and ▁training . ▁There ▁are ▁many ▁technical ▁training ▁organis ations : ▁see ▁the ▁Techn ical ▁D iving ▁section ▁in ▁the ▁list ▁of ▁diver ▁cert ification ▁organizations . ▁Techn ical ▁D iving ▁International ▁( T DI ), ▁Global ▁Under water ▁Ex pl or ers ▁( G UE ), ▁Professional ▁Sc uba ▁Association ▁International ▁( PS AI ), ▁International ▁Association ▁of ▁N it ro x ▁and ▁Techn ical ▁D ivers ▁( I ANT D ) ▁and ▁National ▁Association ▁of ▁Under water ▁Inst ruct ors ▁( NA UI ) ▁were ▁popular ▁. ▁Rec ent ▁entries ▁into ▁the ▁market ▁include ▁Un ified ▁Team ▁D iving ▁( UT D ), ▁Inner Space ▁Ex pl or ers ▁( I SE ) ▁and ▁D iving ▁Science ▁and ▁Technology ▁( DS AT ), ▁the ▁technical ▁arm ▁of ▁Professional ▁Association ▁of ▁D iving ▁Inst ruct ors ▁( P AD I ). ▁The ▁Sc uba ▁School s ▁International ▁( SS I ) ▁Techn ical ▁D iving ▁Program ▁( T ech X R ▁– ▁Techn ical ▁e X t ended ▁Range ) ▁was ▁launched ▁in ▁ 2 0 0 5 . ▁ ▁British ▁Sub - A qua ▁Club ▁( BS AC ) ▁training ▁has ▁always ▁had ▁a ▁technical ▁element ▁to