PADI Open Water Exam Study Guide 2024
with Correct Solutions
When is an object positively buoyant? - Answer -When it displaces a volume of water weighing more
than its own weight.
When is an object negatively buoyant? - Answer -When it displaces a volume of water weighing less than
its own weight.
When is an object neutrally buoyant? - Answer -When it displaces a volume of water weighing the same
as its own weight.
Why two pieces of equipment do you use to control your buoyancy? - Answer -BCD, Lead weight
What does buoyancy help with when you are underwater? - Answer -Controlling where you are
What does buoyancy help with when you are at the surface? - Answer -Floatation, conserving energy
How does the buoyancy of an object differ in fresh/salt water? - Answer -More buoyant in salt than fresh
When you exhale what happens? - Answer -Lung volume decreases so you have less buoyancy.
When you inhale what happens? - Answer -Lung volume increases so you have more buoyancy.
Why don't you feel air pressure? - Answer -Your body is primarily liquid, which is incompressible and
distribute pressure equally throughout your whole body.
Where are some air spaces located in the body? - Answer -Ears, sinuses, lungs
Do you always feel the pressure in body air spaces? - Answer -Only if the pressure is different inside and
outside the air spaces.
1 bar is what depth? - Answer -0m/0ft
2 bar is what depth? - Answer -33ft/10m
3 bar is what depth? - Answer -66ft/20m
4 bar is what depth? - Answer -99ft/30m
How is air volume affected when depth is increased? - Answer -It decreases
How is air density affected when depth is increased? - Answer -It increases
, What happens if you take an air volume underwater with you in a flexible container or inverted jar? -
Answer -As pressure increases the volume decreases, same air but smaller space.
How do you maintain air volume as you descend? - Answer -Equalize
What is a "squeeze"? - Answer -As volume decreases, pressure pushes body tissues inwards toward air
space, causing discomfort. Pressure outside air space is more than pressure inside air space.
Where can you get a squeeze? - Answer -Ears, sinuses, mask, lungs, teeth
How do you equalise air spaces in ears? - Answer -Blow and squeeze nose, wiggle jaw, swallowing
How often should you equalise? - Answer -Every metre before discomfort
What do you do if you feel discomfort? - Answer -Ascend until discomfort eases, equalise, continue
descent slowly
Why can't you scuba while sick? - Answer -Congestion can plug air passages so you can't equalize
What is mask equalisation? - Answer -exhale into mask by nose
What does your nose need to be in the mask? - Answer -To equalize
First rule of diving - Answer -Always breathe continuously
What happens if you hold your breath during ascent? - Answer -Lung over expansion, forces air into
bloodstream and chest cavity, leading to paralysis or death.
What is a reverse block? - Answer -When air cannot escape from a air space during ascent
How do you react to reverse block? - Answer -Slow/stop ascent and give air time to work its way out
As you go deeper you use your air ___? - Answer -faster
Why do you wear a mask underwater? - Answer -Light behaves differently in water than in air, which
affects how your eyes focus. Mask creates air space so your eyes can focus.
How do you know a mask fits? - Answer -"Sniff" test
Two most important selection factors when buying scuba equipment is? - Answer -fit and comfort
Features you look for in a mask - Answer -low profile
nose or finger pockets
wide vision field
adjustable strap
with Correct Solutions
When is an object positively buoyant? - Answer -When it displaces a volume of water weighing more
than its own weight.
When is an object negatively buoyant? - Answer -When it displaces a volume of water weighing less than
its own weight.
When is an object neutrally buoyant? - Answer -When it displaces a volume of water weighing the same
as its own weight.
Why two pieces of equipment do you use to control your buoyancy? - Answer -BCD, Lead weight
What does buoyancy help with when you are underwater? - Answer -Controlling where you are
What does buoyancy help with when you are at the surface? - Answer -Floatation, conserving energy
How does the buoyancy of an object differ in fresh/salt water? - Answer -More buoyant in salt than fresh
When you exhale what happens? - Answer -Lung volume decreases so you have less buoyancy.
When you inhale what happens? - Answer -Lung volume increases so you have more buoyancy.
Why don't you feel air pressure? - Answer -Your body is primarily liquid, which is incompressible and
distribute pressure equally throughout your whole body.
Where are some air spaces located in the body? - Answer -Ears, sinuses, lungs
Do you always feel the pressure in body air spaces? - Answer -Only if the pressure is different inside and
outside the air spaces.
1 bar is what depth? - Answer -0m/0ft
2 bar is what depth? - Answer -33ft/10m
3 bar is what depth? - Answer -66ft/20m
4 bar is what depth? - Answer -99ft/30m
How is air volume affected when depth is increased? - Answer -It decreases
How is air density affected when depth is increased? - Answer -It increases
, What happens if you take an air volume underwater with you in a flexible container or inverted jar? -
Answer -As pressure increases the volume decreases, same air but smaller space.
How do you maintain air volume as you descend? - Answer -Equalize
What is a "squeeze"? - Answer -As volume decreases, pressure pushes body tissues inwards toward air
space, causing discomfort. Pressure outside air space is more than pressure inside air space.
Where can you get a squeeze? - Answer -Ears, sinuses, mask, lungs, teeth
How do you equalise air spaces in ears? - Answer -Blow and squeeze nose, wiggle jaw, swallowing
How often should you equalise? - Answer -Every metre before discomfort
What do you do if you feel discomfort? - Answer -Ascend until discomfort eases, equalise, continue
descent slowly
Why can't you scuba while sick? - Answer -Congestion can plug air passages so you can't equalize
What is mask equalisation? - Answer -exhale into mask by nose
What does your nose need to be in the mask? - Answer -To equalize
First rule of diving - Answer -Always breathe continuously
What happens if you hold your breath during ascent? - Answer -Lung over expansion, forces air into
bloodstream and chest cavity, leading to paralysis or death.
What is a reverse block? - Answer -When air cannot escape from a air space during ascent
How do you react to reverse block? - Answer -Slow/stop ascent and give air time to work its way out
As you go deeper you use your air ___? - Answer -faster
Why do you wear a mask underwater? - Answer -Light behaves differently in water than in air, which
affects how your eyes focus. Mask creates air space so your eyes can focus.
How do you know a mask fits? - Answer -"Sniff" test
Two most important selection factors when buying scuba equipment is? - Answer -fit and comfort
Features you look for in a mask - Answer -low profile
nose or finger pockets
wide vision field
adjustable strap
