. ▁As ▁well ▁as ▁being ▁a ▁generic ▁term , ▁' Div em aster ' ▁is ▁the ▁title ▁of ▁the ▁first ▁professional ▁rating ▁of ▁many ▁training ▁ag encies , ▁such ▁as ▁P AD I , ▁S SI , ▁S DI , ▁N ASE , ▁except ▁NA UI , ▁which ▁rates ▁a ▁NA UI ▁Div em aster ▁under ▁a ▁NA UI ▁Inst ruct or ▁but ▁above ▁a ▁NA UI ▁Ass istant ▁Inst ruct or . ▁The ▁div em aster ▁cert ification ▁is ▁generally ▁equivalent ▁to ▁the ▁requirements ▁of ▁ISO   2 4 8 0 1 - 3 ▁D ive ▁Le ader . ▁ ▁The ▁B S AC ▁recogn izes ▁several ▁ag encies ' ▁div em aster ▁certific ates ▁as ▁equivalent ▁to ▁B S AC ▁D ive ▁Le ader , ▁but ▁not ▁to ▁B S AC ▁Advanced ▁D iver . ▁The ▁con verse ▁may ▁not ▁be ▁true . ▁ ▁The ▁cert ification ▁is ▁a ▁pr ere quis ite ▁for ▁training ▁as ▁an ▁instruct or ▁in ▁recre ational ▁div ing ▁with ▁the ▁professional ▁ag encies ▁except ▁NA UI , ▁where ▁it ▁is ▁an ▁optional ▁step , ▁because ▁of ▁the ▁different ▁position ▁of ▁the ▁NA UI ▁Div em aster ▁in ▁the ▁NA UI ▁hierarchy . ▁ ▁Ro le ▁ ▁The ▁role ▁of ▁a ▁div em aster ▁may ▁vary , ▁but ▁will ▁generally ▁include ▁the ▁following ▁roles : ▁ ▁Organ izing , ▁conduct ing ▁and ▁super vis ing ▁recre ational ▁div ing ▁activities ▁( but ▁not ▁training ), ▁both ▁shore ▁and ▁boat ▁based . ▁ ▁Ass isting ▁instruct ors