PADI OPEN WATER DIVE COURSE
KNOWLEDGE REVIEWS 1-5
QUESTIONS & ANSWERS (RATED A+)
Knowledge review 1 - ANSWER
At 10 metres/33 feet you're _____ bar/ata of total pressure and the air density is ___
times as great as at the surface.
a. 1
b. 2
c. 3
d. 4 - ANSWERb. 2
*Pressure increases by one bar/ata for every 10 metres/33 feet of depth. So, at 10
metres/33 feet, the total pressure is 2 bar/ata (one from water pressure and one from
atmospheric pressure). Density increases proportionally, so at 2 bar/ata the density
is 2 times as great, at 3 bar/ata the density is 3 times as great, etc.
*If you can't equalize, stop your descent immediately. Signal your buddy(ies) or
instructor. Ascend slightly until the discomfort passes and try again. If you still can't
equalize, stop the dive. Continuing to descend with unequalized air spaces can lead
to serious injuries!
I should equalize
a. early and often, before I feel discomfort.
b. only if I experience pain.
c. the same as - ANSWERa. early and often, before I feel discomfort.
*Equalize every metre/few feet, before you feel discomfort. If you wait until you feel
discomfort, equalization may be difficult or impossible. When you equalize as often
as you should, you don't feel discomfort or pain.
I should not dive with a cold, nor use medications to dive with a cold.
a. True
b. False - ANSWERa. True
*Never dive with a cold or allergy. They can cause congestion that might block
normal air flow and may make equalization difficult or impossible. Using cold
medications is not recommended. They can wear off during a dive, and can cause
equalization problems as you ascend.
The most important rule in scuba diving is:
, a. Breathe continuously and never hold my breath.
b. Always dive with a buddy.
c. Keep my mask on while in the water, even at the surface.
d. Check my SPG at least every couple of minutes. - ANSWERa. Breathe
continuously and never hold my breath.
*If during ascent you hold your breath, blocking your airway, your lungs would over
expand. Expanding air can cause serious lung overexpansion injuries. For this
reason, the most important rule in scuba diving is to breathe continuously and never,
ever hold your breath.
Failure to follow the most important rule in scuba diving can cause serious lung
overexpansion (lung rupture) injuries, which in turn can cause paralysis and death.
a. True
b. False - ANSWERa. True
*Lung overexpansion injuries are among the worst injuries you can have in diving,
and they are difficult to treat. But, they are also easy to avoid - never hold your
breath while scuba diving.
If I feel discomfort in a body air space while ascending, the correct action is to:
a. Stop, descend slightly and give trapped air time to work its way out.
b. Continue my ascent while blowing against blocked nostrils.
c. Descend at least 10 metres/33 feet, then resume my ascent. - ANSWERa. Stop,
descend slightly and give trapped air time to work its way out.
*If you feel discomfort in any air space during ascent, immediately slow or stop your
ascent. Descend a metre/few feet to reduce the discomfort and give the trapped air
time to work its way out. Ascend more slowly, giving the expanding gas time to exit.
My buddy and I are planning a dive to 18 metres/60 feet. We would expect our air
supply to last ________ at 10 metres/33 feet, all else being the same.
a. longer than
b. shorter than
c. the same as - ANSWERb. shorter than
*Because scuba delivers air at the surrounding pressure, the deeper your depth, the
more air each breath takes from your cylinder. Therefore, the deeper you dive, the
faster you use your air, all else being the same.
During a dive, I swim hard to keep up with a fish that interests me, but shortly begin
to feel like I can't get enough air. The correct action would be to:
a. Signal my buddy and head up to the surface.
b. Use the regulator purge button to boost air flow.
KNOWLEDGE REVIEWS 1-5
QUESTIONS & ANSWERS (RATED A+)
Knowledge review 1 - ANSWER
At 10 metres/33 feet you're _____ bar/ata of total pressure and the air density is ___
times as great as at the surface.
a. 1
b. 2
c. 3
d. 4 - ANSWERb. 2
*Pressure increases by one bar/ata for every 10 metres/33 feet of depth. So, at 10
metres/33 feet, the total pressure is 2 bar/ata (one from water pressure and one from
atmospheric pressure). Density increases proportionally, so at 2 bar/ata the density
is 2 times as great, at 3 bar/ata the density is 3 times as great, etc.
*If you can't equalize, stop your descent immediately. Signal your buddy(ies) or
instructor. Ascend slightly until the discomfort passes and try again. If you still can't
equalize, stop the dive. Continuing to descend with unequalized air spaces can lead
to serious injuries!
I should equalize
a. early and often, before I feel discomfort.
b. only if I experience pain.
c. the same as - ANSWERa. early and often, before I feel discomfort.
*Equalize every metre/few feet, before you feel discomfort. If you wait until you feel
discomfort, equalization may be difficult or impossible. When you equalize as often
as you should, you don't feel discomfort or pain.
I should not dive with a cold, nor use medications to dive with a cold.
a. True
b. False - ANSWERa. True
*Never dive with a cold or allergy. They can cause congestion that might block
normal air flow and may make equalization difficult or impossible. Using cold
medications is not recommended. They can wear off during a dive, and can cause
equalization problems as you ascend.
The most important rule in scuba diving is:
, a. Breathe continuously and never hold my breath.
b. Always dive with a buddy.
c. Keep my mask on while in the water, even at the surface.
d. Check my SPG at least every couple of minutes. - ANSWERa. Breathe
continuously and never hold my breath.
*If during ascent you hold your breath, blocking your airway, your lungs would over
expand. Expanding air can cause serious lung overexpansion injuries. For this
reason, the most important rule in scuba diving is to breathe continuously and never,
ever hold your breath.
Failure to follow the most important rule in scuba diving can cause serious lung
overexpansion (lung rupture) injuries, which in turn can cause paralysis and death.
a. True
b. False - ANSWERa. True
*Lung overexpansion injuries are among the worst injuries you can have in diving,
and they are difficult to treat. But, they are also easy to avoid - never hold your
breath while scuba diving.
If I feel discomfort in a body air space while ascending, the correct action is to:
a. Stop, descend slightly and give trapped air time to work its way out.
b. Continue my ascent while blowing against blocked nostrils.
c. Descend at least 10 metres/33 feet, then resume my ascent. - ANSWERa. Stop,
descend slightly and give trapped air time to work its way out.
*If you feel discomfort in any air space during ascent, immediately slow or stop your
ascent. Descend a metre/few feet to reduce the discomfort and give the trapped air
time to work its way out. Ascend more slowly, giving the expanding gas time to exit.
My buddy and I are planning a dive to 18 metres/60 feet. We would expect our air
supply to last ________ at 10 metres/33 feet, all else being the same.
a. longer than
b. shorter than
c. the same as - ANSWERb. shorter than
*Because scuba delivers air at the surrounding pressure, the deeper your depth, the
more air each breath takes from your cylinder. Therefore, the deeper you dive, the
faster you use your air, all else being the same.
During a dive, I swim hard to keep up with a fish that interests me, but shortly begin
to feel like I can't get enough air. The correct action would be to:
a. Signal my buddy and head up to the surface.
b. Use the regulator purge button to boost air flow.
