PADI IDC Exam Questions and Answers - How to Pass The PADI IE Exam (2024)

You can use the PADI IDC Exam questions and answers on this page for practicing for your PADI IDC Course exams and the PADI IE Exam questions.

There are 2 exams in the PADI IDC course and the PADI IE (Instructor Examination). One is the PADI Standards Exam and the other is the PADI Dive Theory Exam. The PADI Standards Exam is an open-book exam and you can use the PADI Instructor Manual and PADI Guide to Teaching for that. The PADI Theory Exam is closed book and you need to be able to complete that from memory.

In this blog, we will give you these PADI IDC Exam questions and answers exams to practice with for free as some PADI IDC candidates struggle with the PADI Theory exams during the PADI IDC Course.

Learn more about the PADI IDC Skills Circuit here

Another and sometimes much more effective way of practicing the PADI IDC Exam questions and answers is to only focus on one dive theory topic, for example:

​Make Physics 1 (this will just be 12 questions), then check the answers to that. Then check your mistakes and try to learn from them. You can learn from your mistakes using the dive theory Physics summary, google, and/or books, What is important is that you only keep focussing on Physics by making the Physics exam 2. Again only the 12 questions and then check the answers, keep repeating this process until you did all 5 Physics. Then Do the same with the next topic like Physiology etc.

Learn more about mastering your IDC Skills here

Constants:

1 liter of salt water weighs 1.03 kilograms

1 liter of fresh water weighs 1 kilogram

Pressure increases by 1 BAR/ATM every 10 meters of salt water

Pressure increases by 1 BAR/ATM every 10.3 meters of fresh water

Pressure changes per unit of salt water = 0.100 ATM/m

Pressure changes per unit of freshwater = 0.097 ATM/m

Formulas:

Boyle’s Law:

Saltwater:

Absolute pressure = depth / 10 + 1
Ambient pressure = depth / 10 + 1
Gauge pressure = depth / 10

Freshwater:

Absolute pressure = depth / 10.3 + 1
Ambient pressure = depth / 10.3 + 1
Gauge pressure = depth / 10.3

Dalton’s Law:

Percentage x pressure = partial pressure (p.p.)

Charles law:

For every 1 degree Celsius, the pressure increases by 0.6 bar

Archimedes law:

FW Neutral Buoyancy = Substract

SW Neutral Buoyancy = Substrat > Subtract > Devide
SW Positive Buoyancy = Multiple > Subtract > Add > Devide
SW Negative Buoyancy = Multiple > Subtract > Remove the Negative ( - ) > Add

​For TRUE or FALSE Questions: A = TRUE and D = FLASE

​1. Water has the capability to _________ light; because of this __________ color disappearing first underwater.

a. refract / blue
b. absorb / green
c. absorb / red
d. refract / red

2. Sound travels ______ times faster underwater making it difficult for divers to determine the _________ of it.
a. 4 / intensity
b. 20 / cause
c. 4 / cause
d. 4 / origin

3. A scuba tank is filled with an ambient pressure of 10 degrees Celsius. What will happen if this tank is then placed in an environment near 40 degrees Celsius?

a. Volume decreases and pressure within the tank increases.
b. Pressure within the tank decreases and volume is unchanged.
c. Volume increases and pressure within the tank is unchanged.
d. Pressure within the tank increases and volume is unchanged.

4. A diver breathing compressed air from a scuba tank that contains 0.75% of Carbon Monoxide at 45m in seawater would have the same effect as a person breathing what Percent of Carbon Monoxide at the surface?

a. 4.125%
b. 0.75%
c. 3.375%
d. 33.75%

5. A huge anchor weighing 645kg lies at 23m at the bottom of the sea. It displaces 276 liters of water. How much air do you need to add to your lifting device to move it off the bottom?

a. 360 liters
b. 350 liters
c. 284 liters
d. 276 liters

6. What is the absolute pressure at 27m of fresh water?

a. 27 ata
b. 3.7 ata
c. 2.62 ata
d. 3.62 ata

7. A sealed metal container with a volume of 12 liters is taken down into seawater. What is the new volume and what will happen to the density inside the container upon Reaching 20m?

a. Volume – 12 liters and density unchanged.
b. Volume – 24 liters and density are 2 times greater.
c. Volume – 12 liters and density 3 times greater.
d. Volume 36 liters and density 3 times greater.

8. A scuba tank is filled with 35% of oxygen and 65% of nitrogen. What is the partial pressure of nitrogen and oxygen in this tank when breathed at 29m in freshwater?

a. 2.53 ata / 1.36 ata
b. 1.88 ata / 1.01 ata
c. 1.83 ata / 0.98 ata
d. 2.48 ata / 1.33 ata

9. When the pressure of a gas is increased while it is still in contact with a liquid:

a. The liquid evaporates
b. The gas forms bubbles in the liquid
c. The liquid dissolves into the gas
d. The gas dissolves into the liquid

10. An object that is positively buoyant in salt water would ______ in fresh water.

a. Float
b. Unable to determine with the information given
c. Sink slowly
d. Be Neutrally buoyant

11. An object weighing 67kg is negatively buoyant in fresh water and neutrally buoyant in salt water. What is the exact volume of this object?

a. 67 liters
b. 65 liters
c. 69 liters
d. Cannot be determined with the information given

12. Under certain conditions, underwater objects appear to be further away than it actually is; this phenomenon is known as _______ and it is primarily caused by _______.
​
a. Visual reversal / Turbidity
b. Visual disturbance / Saltwater
c. Refraction / Light travels at different speed underwater
d. Absorption / Density of the water

1. Carotid Sinus reflex results in __________ primarily caused by _____________.

a. Automatic bleeding of sinuses / the inability to equalize airspaces
b. Slowing of the heart / wearing a tight-fitting hood or wetsuit constricting blood flow through the carotid arteries.
c. Lung squeeze/descending too fast
d. Slowing of heart/exhaling too much while descending.

2. Divers are advised not to hyperventilate excessively when doing breath-hold diving to avoid:

a. Thoracic squeeze
b. Carbon monoxide poising
c. Hypocapnia
d. Shallow water blackout

3. When diving divers need to breathe slowly and deeply and use a well-maintained regulator to reduce the risk of:

a. Hypocapnia
b. Thoracic squeeze
c. Hypercapnia
d. Carbon monoxide poisoning

4. Oxygen is administered to divers suspected of having decompression illness to:

a. Decrease Hypocapnia
b. Increase metabolism of nitrogen
c. Lower the partial pressure of nitrogen which helps to safely accelerate the diffusion of nitrogen from the blood
d. All of the above

5. After a dive, even though divers do not display any DCI signs and symptoms, tiny nitrogen bubbles referred as _______________ are thought to form in the circulatory system because of the presence of _____________.

a. Invisible/gas “seeds”
b. Microbubbles / nitrogen
c. Silent bubbles/gas “seeds”
d. Silent bubbles/impurities in the air supply

6. __________________ is a substance contained within the ______ blood cells that aids in transportation of oxygen throughout the body.

a. Hemoglobin / red
b. Plasma / red
c. Cholesterol / red
d. Hemoglobin / white

7. Air bubbles entering arteries and blocking blood flow would indicate that the diver is suffering from which lung expansion injuries?

a. Pneumothorax
b. Mediastinal emphysema
c. Subcutaneous emphysema
d. Air embolism

8. A diver having difficulty equalizing while descending, who forcefully blows against a pinched nose, has a high risk of __________.

a. Hypoxia
b. Rupturing his round window
c. Rupturing his eardrum
d. Rupturing his Eustachian tube

9. A diver with a strong rapid pulse, not sweating and hot dry skin is suffering from:

a. Heat Exhaustion
b. Jellyfish stings
c. Heatstroke
d. Advanced Hypothermia

10. Advanced hypothermia signs and symptoms includes:

a. Strong rapid pulse, no perspiration, and hot skin
b. Cool and clammy skin, nausea
c. No shivering, drowsiness lack of coordination, and possibly coma
d. Shivering, numbness in fingers and toes

11. Gas exchange between the tissues and the blood occurs in the:

a. Capillaries
b. Arteries
c. Heart
d. Veins

12. Carbon monoxide bonds with hemoglobin over _______ times better than oxygen can.
​
a. 20
b. 200
c. 300
d. 4

1. When using the RDP for diving higher than 300m, you need to follow these procedures except for:

a. Wait a minimum of 6 hours upon reaching the altitude before diving
b. Slower ascent rate of 9m per minute
c. Actual depths must be converted to theoretical depths
d. When changing altitude, dive at the lowest altitude first

2. A __________ tissue compartment model was used to determine No decompression limits and the surface interval credit was calculated using _______________________ to form the RDP.

a. 12 / 120 minutes
b. 14 / 120 minutes
c. 14 / 60 minutes
d. 7 / 60 minutes

3. RDP is using a much faster “gas wash out” compartment compared to the US Navy table. The benefit of using RDP for recreational diving is that it:

a. Provides longer no decompression time
b. Provides shorter required surface interval time
c. Provides longer surface interval time but longer no decompression time for deep dives
d. Provides equal surface interval time but longer no decompression time

4. When diving in a group of divers who use dive computers we should follow the limits of:

a. Diver with the latest dive computer
b. Diver with the most conservative computer
c. Diver with the most experience
d. Diver with the least experience

5. Because they are based on (the) _______________ theoretical model(s), pressure groups __________________ between the Table and the ERDPML.

a. Different / cannot be transferred
b. Different / can be transferred
c. Same / can be transferred
d. Same / cannot be transferred

6. A diver has been doing two dives for four consecutive days. What is the minimum time he has to wait before he is allowed to fly in a commercial airliner according to the RDP?

a. 12 hours
b. 8 hours
c. 24 hours
d. 18 hours

Use the eRDP ML or RDP table to answer the following problems. Although you would normally dive well within maximum limits, for examination purposes provide the required answers as exactly as possible according to the Planner.

7.A diver enters the water for his first dive at 0830 hours on a dive to 24m for 20 minutes. At 0918 hour he re-enters the water on a dive to 18m for 32 minutes. What is his maximum allowable time for another dive to 17m after 58 minutes surface interval?

a.30 minutes
b.26 minutes
c.53 minutes
d.19 minutes

8. After a 20m dive for 40 minutes, a diver would like to make a second dive to the same depth for 28 minutes and he also plans to go to 16m for 42 minutes for his third dive. What are the minimum surface intervals between his first and second dive as well as between his second and his third dive?

a.1:08 and 0:48
b.1:15 and 0:48
c.1:15 and 0:53
d.1:08 and 0:53

9. After 27 minutes of diving at 19m, a diver decides to ascend because he is feeling cold and tired of swimming against the current. What is his maximum allowable depth for his next dive in a normal environment if he wants to spend at least 35 minutes underwater after a 55 minutes surface interval?

a.23m
b.20m
c.16m
d.18m

Use the eRDP ML to answer the following problems. Although you would normally dive well within maximum limits, for examination purposes provide the required answers as exactly as possible according to the eRDP ML.

10. A diver plans to do a multilevel dive starting from 32, up to 19m and 12m. He wishes to stay according to all the maximum time limits. How long will he be able to stay underwater in total, including a safety stop (if required)?

a.77 mins
b.80 mins
c.83 mins
d.17 mins

11. At 11:05 a.m. a diver enters the water to do his first dive to 24m for 27 minutes. If he uses minimum surface intervals to plan for his second dive to 22m for 25 minutes, what time will he come back up to the surface after both dives? (You may ignore all ascent times but NOT required safety stop time)

a.Can not determine the answer with the information given
b.13:03
c.13:14
d.13:20

12. What is the ending pressure group at the end of a multilevel dive starting at 24m for 22 minutes then up to 20m for 11 minutes and 12m for 15 minutes?
​
a.L
b.S
c.P
d.Dive profile can’t be done

​1. A diver who is injured by an aquatic life may have the following signs and symptoms except for:

a. Respiratory and cardiac arrest
b. Local excruciating pain
c. Local swelling or inflammation
d. Cherry red lips and nail beds

2. During a deep dive, you notice a diver is behaving foolishly, the best way to assist this diver is to:

a. Take him up to a shallower depth
b. Take him to a deeper depth
c. Tell him to breathe slowly and deeply
d. Tell him to monitor his air supply and swim horizontally until he feels better

3. In the ______________ hemisphere the major ocean currents flow counter-clockwise, while in the _________________ hemisphere they flow clockwise.

a. Northern / Southern
b. Southern / Northern
c. Western / Eastern
d. Eastern / Western

4. The two major environmental elements that cause currents in the ocean are:

a. Water temperature and upwelling
b. Earth’s rotation and wind
c. Tide and gravitational pull from the sun and the moon
d. All of the above

5. You lost a dive knife in an area of flat sandy bottom where visibility is usually limited. Which search pattern is the most appropriate to find this object?

a. “U” pattern with a compass
b. Sweeping “V” formation
c. Expanding circular using line
d. Square pattern

6. A diver is wearing a BCD with 16kg of lift. After a few minutes, underwater he finds an anchor, and he realizes that he could not lift this anchor unless he fills his BCD completely. What action should he take in this circ*mstance?

a. Hold the anchor lightly, inflate his BCD, ascend slowly, and be ready to release air in case he is ascending too fast
b. Tie a line to the anchor and attach it to his buddy and his BCD, inflate both BCD partially and swim up slowly
c. Leave the anchor at the bottom and come back with a lifting device later
d. Kick up as hard as possible while holding the anchor with his buddy with both BCDs fully deflated

7. When diving at altitude, although the percentage of gases within the atmosphere remains the same, the _________________ of the gases will _____________________.

a. Partial pressure / increase
b. Viscosity / decrease
c. Tension / increase
d. Partial pressure / decrease

8. A diver surfaces and immediately complains that he is feeling really dizzy and has difficulty in breathing. He more likely is suffering from ________ rather than ____________.

a.Lung expansion injury / Decompression sickness
b.Decompression sickness / lung expansion injury
c.Carbon monoxide poisoning / oxygen toxicity
d.Oxygen toxicity / Carbon monoxide poisoning

9. When administering one rescuer adult CPR, the compression rate should be:

a.80 per minute
b.100 per minute
c.120 per minute
d.60 per minute

10. The primary concern in dealing with an unconscious diver on the surface is to:

a.Check for breathing
b.Remove their equipment
c.Check for pulse
d.Locate his buddy to determine what happened

11. When doing shore dives you can use ripple marks (when present) as a navigation aid as you know they usually run:

a.Diagonally to the shoreline
b.Parallel to the shoreline
c.Ninety-degree angle to the shoreline
d.Forty-five-degree angle to the shoreline

12. In the unlikely event you are out of the air in shallow water and your buddy is too far away you should:
​
a.Drop your weight belt and swim slowly to the surface
b.Swim slowly towards your buddy and try to get his attention by rapping your tank repeatedly
c.Swim no faster than 18m per minute towards the surface, looking up while exhaling by making a continuous “ahhhh” sound
d.Swim no faster than 18m per minute towards the surface while holding your breath as long as possible​

1. If you accidentally expose your scuba tank to a temperature or heat greater than ______________ you should have it ______________ before using the tank again.

a. 90 degrees Celsius / hydrostatically tested
b. 182 degrees Celsius / visually inspected
c. 82 degrees Celsius / hydrostatically tested
d. 100 degrees Celsius / visually inspected

2. During hydrostatic testing, the tester will immerse the scuba tank in ____________ and fill it with _________________.

a. Water / air
b. Sea water / water
c. Water / water
d. Oil / water

3. The type of scuba regulator that screws directly into the tank valve is known as _______________ and is useful for ____________ diving.

a. K valve / cold water
b. DIN / overhead environment (e.g. cave and wreck penetration)
c. J valve / technical
d. Pilot / overhead environment (e.g. cave and wreck penetration)

4. The most significant equipment malfunction that can be directly linked to causing Decompression Sickness include:

a. Problem with leaking mask, broken fin strap
b. Failing to inflate BCD underwater to positively neutral
c. Diving with an unfamiliar compass in an unfamiliar dive site
d. Failing to monitor the depth and timing device

5. When diving with a downstream valve regulator, it would _________ in the event of the regulator malfunction. This design is also known as ____________________.

a. Free flow / fail safe
b. Stop delivering air / fail-proof
c. Free flow / automatic lock
d. Deliver less air / fail safe

6. After a few days of diving with aluminum tanks, a diver decides to use a steel tank for his first dive today. What kind of equipment adjustments would he need to consider before he dives with the steel tank?

a. He needs to decrease the amount of weight he is using because the steel tank is less buoyant.
b. He needs to increase the amount of weight he is using because the steel tank has a thicker wall.
c. He needs to position the steel tank lower on his BCD strap because steel tanks are smaller than aluminum tanks.
d. He needs to decrease the amount of weight he is using because the aluminum tank has thinner walls.

7. The benefits of using a balanced regulator as opposed to an unbalanced regulator are:

a.Delivers air at the same rate even if tank pressure is low
b.Tank air pressure neither helps nor resists the opening of the valves
c.Deliver air at the same rate if more than two divers breathing from the same regulator at once
d.All of the above

8. A diaphragm that opens a smaller valve that opens the main valve by creating a pressure imbalance is called ________________ and is found in the regulator _____________________.

a.Downstream valve / second stage
b.Upstream valve / first stage
c.Pilot valve / second stage
d.Pilot valve / first stage

9. _________________ gauge is designed according to ______________ law and is suitable for __________ diving.

a.Capillary / Boyle’s / Altitude
b.Open bourdon / Boyle’s / Deep
c.Closed Bourdon / Dalton’s / Altitude
d.Capillary / Dalton’s / Deep

10. Which of these best describes the function of a regulator's first stage?

a.Reduce high pressure from the tank to ambient pressure
b.Reduce high pressure from the tank to an intermediate pressure
c.Reduce intermediate pressure from the tank to breathing pressure
d.Reduce high pressure to comfortable breathing pressure

11.When diving in extremely cold water, a regulator that has a(n) _____________ may be protected from ____________.

a.Downstream valve / heat
b.Environmental Seal / freezing up
c.Fail-safe designed / freezing up
d.Closed circuit / heat

12. As a diver inhales using a typical regulator second stage:
​
a.A piston opens a valve releasing air from the tank
b.A small valve opens the main valve, which releases air from the tank
c.A diaphragm is depressed opening a valve releasing air from the first stage
d.Air is automatically released from the first stage because of an imbalance in pressure inside the second stage

​Well done on completing your first PADI IDC Exam questions. Below you will find the PADI IDC Exam answers for these questions so you can correct yourself and learn from any mistakes.

If you would like to practice with more PADI IDC Exams and be fully prepared for your PADI IE then we have 4 more practice exams that you can get by buying me a coffee! Please click the link here to get your full set of PADI IDC and IE Practices Exams with all questions and answers.

1. ​C
2. D
3. D
4. A
5. B
6. D
7. A
8. D
9. D
10. B
11. B
12. A

1. B
2. D
3. C
4. C
5. C
6. A
7. D
8. B
9. C
10. C
11. A
12. B

1. D
2. C
3. B
4. B
5. C
6. D
7. A
8. A
9. D
10. B
11. D
12. D

1. ​D
2. A
3. B
4. B
5. C
6. C
7. D
8. A
9. B
10. A
11. B
12. C

1. C
2. C
3. B
4. D
5. A
6. A
7. D
8. C
9. A
10. B
11. B
12. C

​We hope that this PADI IDC Exam questions and answers page helped you prepare for your PADI IDC and IE Exam and if you click Buy me a Coffee you can get 4 more PADI IDC Practice Exam questions and answers to make sure you will ACE the Real PADI IE Exam!

Also if you want to learn Scuba Dive Theory from me in person then you can join my PADI IDC Course that I start every month at Sairee Cottage Diving in Koh Tao, Thailand. Visit my website here and get in contact as I would love to send you more information about our program.

Best of success all!!