SDI(SCUBA DIVING INTERNATIONAL)
QUESTIONS AND ANSWERS WITH
VERIFIED SOLUTIONS (GRADED A+)
GUARANTEED SUCCESS ALL
INCLUSIVE EXAM GUIDE ||NEWLY
UPDATED 2025
,SDI (Scuba Diving International) Part 2
Questions And Answers With Verified
Solutions
What is the absolute pressure (in atmospheres/bars, ATM) at 20 meters(66 feet) -
ANSWER✔✔ 2 ATM
What will be the volume in a ball that is filled with two cubic feet of air at 99 feet
when it's taken to the surface? - ANSWER✔✔ 8 cubic feet
How many more times dense is the air in a balloon at 4 ATM/bar compared to the
air density at the surface? - ANSWER✔✔ 4x (4 times)
If a scuba cylinder lasts 2 hours at sea level, how long will it last at 20 meters (66
feet)? - ANSWER✔✔ 40 minutes
How often should a scuba diver equalize during a descent? - ANSWER✔✔ at the
surface and every couple of feet as you descend.
What should you do if you experience discomfort in your ears upon descending? -
ANSWER✔✔ Stop and ascend a few feet until you no longer feel any
discomfort. Try to equalize again and continue with your descent.
What is a reverse block? - ANSWER✔✔ When air cannot escape from a air
space during ascent
,What should you do if you experience a reverse block upon ascending? -
ANSWER✔✔ Descend a couple of feet until the pain subsides, wait a minute,
and continue your ascent.
What is the most important rule in scuba diving? - ANSWER✔✔ keep breathing
and never hold your breath
What is the most serious injury that a diver could suffer from if they hold their
breath upon ascending? - ANSWER✔✔ lung over-expansion injury or ruptured
lung
Which gas component in air causes decompression sickness and narcosis? -
ANSWER✔✔ nitrogen
What medical problem can occur if a diver ascends much too rapidly for nitrogen
to be slowly released? - ANSWER✔✔ It can come out of solution into your
blood making bubbles which collect at your joints causing the bends or
decompression sickness.
List at least 5 factors that can predispose a diver to decompression sickness. -
ANSWER✔✔ obesity, age, illness, injuries, repetitive dives, dehydration, fatigue,
use of drugs or alcohol
Describe the symptoms of DCS, including mild to severe signs and symptoms. -
ANSWER✔✔ Joint pain is the most common symptom, a rash or crackling skin
may appear if bubbles occur in the capillaries near the skin, difficulty breathing,
dry cough, dizziness, numbness, tingling, paralysis, temporary blindness,
unconsciousness, permanent disability or death.
, What is the depth threshold where most scuba divers generally begin to be
affected by nitrogen narcosis. - ANSWER✔✔ 30 meters or 100 feet and greater
List two possible ways a diver may feel if they become "narked" at depth.
"rapture of the deep" - ANSWER✔✔ extreme anxiety an euphoria
What should a diver do to alleviate the symptoms of nitrogen narcosis? -
ANSWER✔✔ Ascend normally until you no longer feel the effects.
Which gas causes extreme headache and nausea, and in high enough
concentrations causes unconsciousness and the lips and fingernail beds to turn
bright red? - ANSWER✔✔ Carbon monoxide
What may indicate that the air in a scuba cylinder is harmful to consume? -
ANSWER✔✔ the smell or taste, do not use air that has an odor or taste
What should you do if you suddenly feel sick and develop a headache during a
scuba dive? - ANSWER✔✔ Immediately abort the dive by making a controlled
ascent to the surface.
Questions And Answers From SDI
Quizzes With Verified Solutions Rated
A+
Objects under water appear: - ANSWER✔✔ both closer and larger than they do
on land
QUESTIONS AND ANSWERS WITH
VERIFIED SOLUTIONS (GRADED A+)
GUARANTEED SUCCESS ALL
INCLUSIVE EXAM GUIDE ||NEWLY
UPDATED 2025
,SDI (Scuba Diving International) Part 2
Questions And Answers With Verified
Solutions
What is the absolute pressure (in atmospheres/bars, ATM) at 20 meters(66 feet) -
ANSWER✔✔ 2 ATM
What will be the volume in a ball that is filled with two cubic feet of air at 99 feet
when it's taken to the surface? - ANSWER✔✔ 8 cubic feet
How many more times dense is the air in a balloon at 4 ATM/bar compared to the
air density at the surface? - ANSWER✔✔ 4x (4 times)
If a scuba cylinder lasts 2 hours at sea level, how long will it last at 20 meters (66
feet)? - ANSWER✔✔ 40 minutes
How often should a scuba diver equalize during a descent? - ANSWER✔✔ at the
surface and every couple of feet as you descend.
What should you do if you experience discomfort in your ears upon descending? -
ANSWER✔✔ Stop and ascend a few feet until you no longer feel any
discomfort. Try to equalize again and continue with your descent.
What is a reverse block? - ANSWER✔✔ When air cannot escape from a air
space during ascent
,What should you do if you experience a reverse block upon ascending? -
ANSWER✔✔ Descend a couple of feet until the pain subsides, wait a minute,
and continue your ascent.
What is the most important rule in scuba diving? - ANSWER✔✔ keep breathing
and never hold your breath
What is the most serious injury that a diver could suffer from if they hold their
breath upon ascending? - ANSWER✔✔ lung over-expansion injury or ruptured
lung
Which gas component in air causes decompression sickness and narcosis? -
ANSWER✔✔ nitrogen
What medical problem can occur if a diver ascends much too rapidly for nitrogen
to be slowly released? - ANSWER✔✔ It can come out of solution into your
blood making bubbles which collect at your joints causing the bends or
decompression sickness.
List at least 5 factors that can predispose a diver to decompression sickness. -
ANSWER✔✔ obesity, age, illness, injuries, repetitive dives, dehydration, fatigue,
use of drugs or alcohol
Describe the symptoms of DCS, including mild to severe signs and symptoms. -
ANSWER✔✔ Joint pain is the most common symptom, a rash or crackling skin
may appear if bubbles occur in the capillaries near the skin, difficulty breathing,
dry cough, dizziness, numbness, tingling, paralysis, temporary blindness,
unconsciousness, permanent disability or death.
, What is the depth threshold where most scuba divers generally begin to be
affected by nitrogen narcosis. - ANSWER✔✔ 30 meters or 100 feet and greater
List two possible ways a diver may feel if they become "narked" at depth.
"rapture of the deep" - ANSWER✔✔ extreme anxiety an euphoria
What should a diver do to alleviate the symptoms of nitrogen narcosis? -
ANSWER✔✔ Ascend normally until you no longer feel the effects.
Which gas causes extreme headache and nausea, and in high enough
concentrations causes unconsciousness and the lips and fingernail beds to turn
bright red? - ANSWER✔✔ Carbon monoxide
What may indicate that the air in a scuba cylinder is harmful to consume? -
ANSWER✔✔ the smell or taste, do not use air that has an odor or taste
What should you do if you suddenly feel sick and develop a headache during a
scuba dive? - ANSWER✔✔ Immediately abort the dive by making a controlled
ascent to the surface.
Questions And Answers From SDI
Quizzes With Verified Solutions Rated
A+
Objects under water appear: - ANSWER✔✔ both closer and larger than they do
on land
