▁om issions ▁- ▁the ▁task ▁loading ▁for ▁a ▁C CR ▁diver ▁during ▁critical ▁phases ▁of ▁a ▁d ive ▁is ▁greater ▁than ▁for ▁open ▁circuit ▁sc uba ▁equipment , ▁The ▁circumstances ▁of ▁technical ▁div ing ▁generally ▁mean ▁that ▁errors ▁or ▁om issions ▁are ▁likely ▁to ▁have ▁more ▁serious ▁consequences ▁than ▁in ▁normal ▁recre ational ▁div ing , ▁and ▁there ▁is ▁a ▁t endency ▁towards ▁compet it iveness ▁and ▁risk ▁taking ▁among ▁many ▁technical ▁divers ▁which ▁appears ▁to ▁have ▁contributed ▁to ▁some ▁well ▁public ized ▁acc idents . ▁ ▁Some ▁errors ▁and ▁fail ures ▁that ▁have ▁repeatedly ▁been ▁imp licated ▁in ▁technical ▁div ing ▁acc idents ▁include : ▁ ▁In correct ▁gas ▁switch es ▁in ▁open ▁circuit ▁div ing ; ▁The ▁gas ▁could ▁be ▁hy po xic , ▁with ▁a ▁risk ▁of ▁black out , ▁hyper ox ic , ▁with ▁a ▁risk ▁of ▁o xygen ▁to x icity ▁se iz ure , ▁or ▁have ▁an ▁excess ively ▁high ▁partial ▁pressure ▁of ▁nit ro gen , ▁with ▁a ▁risk ▁of ▁nit ro gen ▁nar cos is . ▁▁ ▁Having ▁an ▁incorrect ▁gas ▁in ▁a ▁cyl inder ▁resulting ▁in ▁hy po x ia , ▁hyper ox ia , ▁nit ro gen ▁nar cos is ▁or ▁in ade qu ate ▁decom pression , ▁usually ▁a ▁consequence ▁of ▁failure ▁to ▁analy se ▁all ▁the ▁mix es ; ▁ ▁In correct ▁gas ▁consumption ▁calculations ▁and ▁failure ▁to ▁monitor ▁usage ▁and ▁change ▁plans ▁during ▁the ▁d ive , ▁causing ▁running ▁out ▁of ▁gas ; ▁ ▁Los ing ▁st aged ▁decom pression