PADI, OPEN WATER DIVER, FINAL
EXAM REVIEW QUESTIONS AND
ANSWERS
Saltywateryisyheavierythanyfreshywaterybecauseyityhasydissolvedymineralsyinyit.y
Thisymeansyitycausesymoreyupwardyforcey(buoyancy)yonyanyobject.yAnyobjectyth
atyisyneutrallyybuoyantyinyfreshywaterywouldyfloatyinysaltywaterybecauseythereyis
ygreateryupwardyforce.y
SeeyBeingyayDiveryIy-yBuoyancyyandyControllingyBuoyancy.y-yans-
1)yIfyanyobjectyisyneutrallyybuoyanty(doesynotysinkyoryfloat)yinyfreshywater,ythey
sameyobjectyplacedyintoysaltywaterywould
Aysink.
Byeitherysinkyoryfloat.
Cydoynothing.
Dyfloat.
ByTheyballoonywillygetysmalleryandytheyairyinsideytheyballoonywillybeymoreydens
ey(moleculesymoveycloserytogether).
Asywaterypressureyincreases,ytheyvolumeyofyanyairyspaceywillydecrease.yThisyca
usesytheydensityyofytheyairyinsideytoyincreaseyandyairymoleculesyareypushedyclo
serytogether.yTheyballoonywouldygetysmalleryandytheyairydensityyinsideywouldybe
ygreater.y
SeeyBeingyayDiveryIy-yWateryPressureyandyAiryVolumeyEffects.y-yans-
2)yIyblowyupyayballoon,ytieyityoff,yandytakeyitytoytheybottomyofytheyswimmingyp
ool.yWhatywillyhappenytoytheyballoonyandytheyairyinsideyit?
AyTheyballoonywillygetybiggeryandytheyairyinsideytheyballoonywillybeylessydense
y(moleculesymoveyfurtheryapart).
ByTheyballoonywillygetysmalleryandytheyairyinsideytheyballoonywillybeymoreydens
ey(moleculesymoveycloserytogether).
CyTheyballoonywillygetybiggeryandytheyairyinsideytheyballoonywillybeymoreydens
e.
DyTheyballoonywillygetysmalleryandytheyairyinsideytheyballoonywillybeylessydense
.
,Aybecomeyhalfytheysizeyitywasyatytheysurface.
Aty10ymeters,ytheypressureyisy2ybar.yAnyairyvolumeytakenytoythisydepthyfromyth
eysurfaceywouldydecreaseyandybecomeyhalfytheysize.y
SeeyBeingyayDiveryIy-yWateryPressureyandyAiryVolumeyEffects.y-yans-
3)yIyturnyayglassyupsideydown,ytrapytheyairyinyitybyyputtingyityinywater,yandythe
nyIytakeytheyglassydownytoy10ymeters.yTheyairyspaceywould
Aybecomeyhalfytheysizeyitywasyatytheysurface.
Bynotychangeyinysize.
Cybecomey1/3ytheysizeyitywasyatytheysurface.
Dybecomey2/3ytheysizeyitywasyatytheysurface.
CyAycold,yallergyyoryanotherymedicalyproblem.
Aycold,yoryanyycongestion,ycanyblockyairypassagesyinyyouryearsyandysinuses,ym
akingyequalizationydifficultyoryimpossible.y
SeeyBeingyayDiveryIy-
yTheyEffectsyofyIncreasingyPressureyonyBodyyAirySpaces.y-yans-
4)yIfyIyamynotyableytoyequalizey(clear)ymyybodyyairyspaces,yitymayybeybecause
yIyhave
Ayseasickness.
Byheartydiseaseyandyhighybloodypressure.
Cyaycold,yallergyyoryanotherymedicalyproblem.
Dyanxiety.
CyIyamyfeelingyaysqueezeyandyneedytoyequalize.
Painyinyyouryearsyorysinusesymeansythatytheyyaren'tyequalized.yStopyyourydesce
ntyandyascendyslightlyytoyrelieveypressureyonyyouryears.yThenyattemptytoyequali
zeyagain.yIfyyouycan'tyequalize,yendytheydive.y
SeeyBeingyayDiveryIy-
yTheyEffectsyofyIncreasingyPressureyonyBodyyAirySpaces.y-yans-
5)yIfymyyearsyorysinusesyhurtywhileyIyamydescendingy(goingydown),yityusuallyym
eans
Aymyyairyspacesyareyequalized.
Bymyymaskystrapyisytooytight.
CyIyamyfeelingyaysqueezeyandyneedytoyequalize.
Dymyymaskyisytooysmall.
, ByInytheytriangleyareayformedybyymyychinyandytheylowerycornersyofymyyribycag
e.
Youryalternateyairysourceyattachesywithyayquickyreleaseyinytheytriangleyareayform
edybyyyourychinyandytheylowerycornersyofyyouryribycage.yAvoidylettingyyouryalte
rnateyairysourceydangleyunsecuredyfromyyourykit.y
SeeyEquipmentyIy-yRegulators.y-yans-
6)yTheybestyplaceyforymeytoypositionyanyalternateyairysourceyis
y
AylooseybyymyysideysoyIycanyfindyityfast.
Byinytheytriangleyareayformedybyymyychinyandytheylowerycornersyofymyyribycag
e.
Cytoytheybaseyofymyycylinder.
DytoytheybackyofymyyBCDybetweenymyyshoulderybladesyandywaist.
DyHoldingymyybreathywhileyscubaydiving.
Blockingyoffyyourylungsybyyholdingyyourybreathyandyascendingycouldycauseythem
ytoyoverexpandyandyrupture,ywhichyisyayseriousyinjuryythatycouldyresultyinyparaly
sisyandydeath.yBreathingycontinuouslyywhileyscubaydivingykeepsyairypassagesyop
enyallowingyexpandingyairytoyescape.y
SeeyBeingyayDiveryIy-
yTheyEffectsyofyDecreasingyPressureyonyBodyyAirySpaces.y-yans-
7)yLungyoverexpansionyinjuriesycanybeycausedyby
y
Ayscubaydivingywithoutyaybuddy.
Bycontinuingyaydiveywhenynotyproperlyyweighted.
Cynotydrinkingyenoughywaterybeforeyscubaydiving.
Dyholdingymyybreathywhileyscubaydiving.
By20yminutes
60/3=20
Foryeachy10ymetersyweygoydown,yweyhaveyoneymoreyatmosphereyofypressure.y
Also,yrememberytoyaddyinythey1yatmosphereyofypressureyatytheysurface.
So,ygoingydownytoy20ymeters,yweywillyhavey2yatmy+y1yatmy=y3yatmyofypressu
re.y-yans-
8)yIfymyycylinderyofyairylastsy60yminutesywhileyIyamyatytheysurfaceybreathingyn
ormally,yassumingyallyelseyisytheysame,yhowylongywillyitylastyaty20ymetersybreat
hingynormally?
Ay60yminutes
EXAM REVIEW QUESTIONS AND
ANSWERS
Saltywateryisyheavierythanyfreshywaterybecauseyityhasydissolvedymineralsyinyit.y
Thisymeansyitycausesymoreyupwardyforcey(buoyancy)yonyanyobject.yAnyobjectyth
atyisyneutrallyybuoyantyinyfreshywaterywouldyfloatyinysaltywaterybecauseythereyis
ygreateryupwardyforce.y
SeeyBeingyayDiveryIy-yBuoyancyyandyControllingyBuoyancy.y-yans-
1)yIfyanyobjectyisyneutrallyybuoyanty(doesynotysinkyoryfloat)yinyfreshywater,ythey
sameyobjectyplacedyintoysaltywaterywould
Aysink.
Byeitherysinkyoryfloat.
Cydoynothing.
Dyfloat.
ByTheyballoonywillygetysmalleryandytheyairyinsideytheyballoonywillybeymoreydens
ey(moleculesymoveycloserytogether).
Asywaterypressureyincreases,ytheyvolumeyofyanyairyspaceywillydecrease.yThisyca
usesytheydensityyofytheyairyinsideytoyincreaseyandyairymoleculesyareypushedyclo
serytogether.yTheyballoonywouldygetysmalleryandytheyairydensityyinsideywouldybe
ygreater.y
SeeyBeingyayDiveryIy-yWateryPressureyandyAiryVolumeyEffects.y-yans-
2)yIyblowyupyayballoon,ytieyityoff,yandytakeyitytoytheybottomyofytheyswimmingyp
ool.yWhatywillyhappenytoytheyballoonyandytheyairyinsideyit?
AyTheyballoonywillygetybiggeryandytheyairyinsideytheyballoonywillybeylessydense
y(moleculesymoveyfurtheryapart).
ByTheyballoonywillygetysmalleryandytheyairyinsideytheyballoonywillybeymoreydens
ey(moleculesymoveycloserytogether).
CyTheyballoonywillygetybiggeryandytheyairyinsideytheyballoonywillybeymoreydens
e.
DyTheyballoonywillygetysmalleryandytheyairyinsideytheyballoonywillybeylessydense
.
,Aybecomeyhalfytheysizeyitywasyatytheysurface.
Aty10ymeters,ytheypressureyisy2ybar.yAnyairyvolumeytakenytoythisydepthyfromyth
eysurfaceywouldydecreaseyandybecomeyhalfytheysize.y
SeeyBeingyayDiveryIy-yWateryPressureyandyAiryVolumeyEffects.y-yans-
3)yIyturnyayglassyupsideydown,ytrapytheyairyinyitybyyputtingyityinywater,yandythe
nyIytakeytheyglassydownytoy10ymeters.yTheyairyspaceywould
Aybecomeyhalfytheysizeyitywasyatytheysurface.
Bynotychangeyinysize.
Cybecomey1/3ytheysizeyitywasyatytheysurface.
Dybecomey2/3ytheysizeyitywasyatytheysurface.
CyAycold,yallergyyoryanotherymedicalyproblem.
Aycold,yoryanyycongestion,ycanyblockyairypassagesyinyyouryearsyandysinuses,ym
akingyequalizationydifficultyoryimpossible.y
SeeyBeingyayDiveryIy-
yTheyEffectsyofyIncreasingyPressureyonyBodyyAirySpaces.y-yans-
4)yIfyIyamynotyableytoyequalizey(clear)ymyybodyyairyspaces,yitymayybeybecause
yIyhave
Ayseasickness.
Byheartydiseaseyandyhighybloodypressure.
Cyaycold,yallergyyoryanotherymedicalyproblem.
Dyanxiety.
CyIyamyfeelingyaysqueezeyandyneedytoyequalize.
Painyinyyouryearsyorysinusesymeansythatytheyyaren'tyequalized.yStopyyourydesce
ntyandyascendyslightlyytoyrelieveypressureyonyyouryears.yThenyattemptytoyequali
zeyagain.yIfyyouycan'tyequalize,yendytheydive.y
SeeyBeingyayDiveryIy-
yTheyEffectsyofyIncreasingyPressureyonyBodyyAirySpaces.y-yans-
5)yIfymyyearsyorysinusesyhurtywhileyIyamydescendingy(goingydown),yityusuallyym
eans
Aymyyairyspacesyareyequalized.
Bymyymaskystrapyisytooytight.
CyIyamyfeelingyaysqueezeyandyneedytoyequalize.
Dymyymaskyisytooysmall.
, ByInytheytriangleyareayformedybyymyychinyandytheylowerycornersyofymyyribycag
e.
Youryalternateyairysourceyattachesywithyayquickyreleaseyinytheytriangleyareayform
edybyyyourychinyandytheylowerycornersyofyyouryribycage.yAvoidylettingyyouryalte
rnateyairysourceydangleyunsecuredyfromyyourykit.y
SeeyEquipmentyIy-yRegulators.y-yans-
6)yTheybestyplaceyforymeytoypositionyanyalternateyairysourceyis
y
AylooseybyymyysideysoyIycanyfindyityfast.
Byinytheytriangleyareayformedybyymyychinyandytheylowerycornersyofymyyribycag
e.
Cytoytheybaseyofymyycylinder.
DytoytheybackyofymyyBCDybetweenymyyshoulderybladesyandywaist.
DyHoldingymyybreathywhileyscubaydiving.
Blockingyoffyyourylungsybyyholdingyyourybreathyandyascendingycouldycauseythem
ytoyoverexpandyandyrupture,ywhichyisyayseriousyinjuryythatycouldyresultyinyparaly
sisyandydeath.yBreathingycontinuouslyywhileyscubaydivingykeepsyairypassagesyop
enyallowingyexpandingyairytoyescape.y
SeeyBeingyayDiveryIy-
yTheyEffectsyofyDecreasingyPressureyonyBodyyAirySpaces.y-yans-
7)yLungyoverexpansionyinjuriesycanybeycausedyby
y
Ayscubaydivingywithoutyaybuddy.
Bycontinuingyaydiveywhenynotyproperlyyweighted.
Cynotydrinkingyenoughywaterybeforeyscubaydiving.
Dyholdingymyybreathywhileyscubaydiving.
By20yminutes
60/3=20
Foryeachy10ymetersyweygoydown,yweyhaveyoneymoreyatmosphereyofypressure.y
Also,yrememberytoyaddyinythey1yatmosphereyofypressureyatytheysurface.
So,ygoingydownytoy20ymeters,yweywillyhavey2yatmy+y1yatmy=y3yatmyofypressu
re.y-yans-
8)yIfymyycylinderyofyairylastsy60yminutesywhileyIyamyatytheysurfaceybreathingyn
ormally,yassumingyallyelseyisytheysame,yhowylongywillyitylastyaty20ymetersybreat
hingynormally?
Ay60yminutes