▁of ▁the ▁planned ▁d ive , ▁but ▁may ▁involve ▁the ▁inter vention ▁of ▁other ▁divers ▁in ▁the ▁team . ▁Stage ▁cyl ind ers ▁may ▁be ▁dropped ▁along ▁the ▁guid eline ▁for ▁later ▁use ▁during ▁the ▁exit ▁or ▁for ▁another ▁d ive . ▁ ▁Equ ip ment ▁configuration ▁ ▁The ▁usual ▁configurations ▁used ▁for ▁increased ▁primary ▁gas ▁supply ▁are ▁manifold ed ▁or ▁independent ▁tw in ▁back ▁mounted ▁cyl ind ers , ▁multiple ▁side ▁mounted ▁cyl ind ers , ▁or ▁re bre athers . ▁B ail out ▁and ▁decom pression ▁gas ▁may ▁be ▁included ▁in ▁these ▁arrang ements , ▁or ▁carried ▁separately ▁as ▁side - mount ed ▁stage ▁and ▁decom pression ▁cyl ind ers . ▁C yl ind ers ▁may ▁carry ▁a ▁variety ▁of ▁g ases ▁depending ▁on ▁when ▁and ▁where ▁they ▁will ▁be ▁used , ▁and ▁as ▁some ▁may ▁not ▁support ▁life ▁if ▁used ▁at ▁the ▁wrong ▁depth , ▁they ▁are ▁marked ▁for ▁positive ▁identification ▁of ▁the ▁contents . ▁Man aging ▁the ▁larger ▁number ▁of ▁cyl ind ers ▁is ▁an ▁additional ▁task ▁loading ▁on ▁the ▁diver . ▁C yl ind ers ▁are ▁usually ▁l abeled ▁with ▁the ▁gas ▁mixture ▁and ▁will ▁also ▁be ▁marked ▁with ▁the ▁maximum ▁operating ▁depth ▁and ▁if ▁applicable , ▁minimum ▁operating ▁depth . ▁ ▁Gas ▁mix es ▁Techn ical ▁div ing ▁can ▁be ▁done ▁using ▁air ▁as ▁a ▁breath ing ▁gas , ▁but ▁other ▁breath ing ▁gas ▁mi xt ures ▁are ▁commonly ▁used ▁to ▁manage ▁specific ▁problems . ▁Some ▁additional ▁knowledge ▁is ▁required ▁to ▁understand ▁the ▁effects ▁of ▁these ▁g