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100+ Free PADI Divemaster Theory Practice Questions

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2026 Statistics

Key Facts: PADI Divemaster Theory Exam

5 sections

Exam Topics

PADI Standards

75%

Required per Section

PADI Standards

2.5 hours

Time Limit

PADI

The PADI Divemaster Theory Exam is a key milestone for dive professionals. It assesses knowledge in five domains: Physics, Physiology, Equipment, Decompression, and Environment/Skills. The passing score is 75% per section, and study time is typically 30-50 hours.

Sample PADI Divemaster Theory Practice Questions

Try these sample questions to test your PADI Divemaster Theory exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1How does the density of seawater compare to the density of freshwater, and what is its weight per unit volume?
A.Seawater is less dense than freshwater, weighing 1.0 kg/liter (62.4 lbs/cubic foot).
B.Seawater is denser than freshwater, weighing 1.025 kg/liter (64 lbs/cubic foot).
C.Seawater and freshwater have identical densities, both weighing 1.0 kg/liter.
D.Seawater is denser than freshwater, weighing 1.05 kg/liter (68 lbs/cubic foot).
Explanation: Seawater contains dissolved salts, making it denser than freshwater. Seawater weighs approximately 1.025 kg per liter (64 pounds per cubic foot), whereas freshwater weighs 1.0 kg per liter (62.4 pounds per cubic foot). This density difference directly affects a diver's buoyancy and requires different calculations.
2What is the absolute pressure (in atmospheres/bar) at a depth of 20 meters (66 feet) in salt water?
A.2.0 atmospheres absolute (ata)
B.2.6 atmospheres absolute (ata)
C.3.0 atmospheres absolute (ata)
D.4.0 atmospheres absolute (ata)
Explanation: In salt water, hydrostatic pressure increases by 1 atmosphere (atm) for every 10 meters (33 feet) of depth. At 20 meters (66 feet), the hydrostatic pressure is 2.0 atm. Adding the 1.0 atm of atmospheric pressure at the surface gives an absolute pressure of 3.0 atm absolute (3.0 ata).
3According to Boyle's Law, if a flexible container holds 12 liters of air at the surface, what will its volume be at a depth of 30 meters (99 feet) in seawater?
A.6 liters
B.4 liters
C.3 liters
D.2.4 liters
Explanation: At 30 meters (99 feet) in seawater, the absolute pressure is 4.0 ata (1.0 atm atmospheric pressure + 3.0 atm hydrostatic pressure). According to Boyle's Law, volume is inversely proportional to absolute pressure (V2 = V1 / P). Therefore, the volume becomes 12 liters / 4.0 = 3 liters.
4If a diver takes a breath from their scuba cylinder at a depth of 40 meters (132 feet) in seawater, how many times denser is the air in their lungs compared to the surface?
A.4 times denser
B.5 times denser
C.6 times denser
D.3 times denser
Explanation: At 40 meters (132 feet) in seawater, the absolute pressure is 5.0 ata (1.0 atm atmospheric + 4.0 atm hydrostatic). According to Boyle's Law, as pressure increases, gas density increases proportionally. Therefore, the air breathed at this depth is 5 times denser than at the surface.
5A diver is breathing standard air (approximately 21% oxygen and 79% nitrogen) at a depth of 30 meters (99 feet) in seawater. What is the partial pressure of oxygen (PO2) at this depth?
A.0.21 ata
B.0.63 ata
C.0.84 ata
D.1.05 ata
Explanation: At 30 meters (99 feet) in seawater, the absolute pressure is 4.0 ata. Dalton's Law states that the partial pressure of a gas in a mixture is equal to the total pressure multiplied by the fraction of that gas (P_gas = P_total * F_gas). Here, PO2 = 4.0 ata * 0.21 = 0.84 ata.
6To avoid central nervous system (CNS) oxygen toxicity, the maximum recommended partial pressure limit for oxygen is 1.4 ata. What is the maximum operating depth (MOD) for a diver using Enriched Air Nitrox with 36% oxygen (EANx36) in seawater?
A.29 meters (95 feet)
B.33 meters (108 feet)
C.38 meters (125 feet)
D.24 meters (79 feet)
Explanation: First, calculate the maximum absolute pressure using Dalton's Law: P_total = P_O2 / F_O2 = 1.4 ata / 0.36 = 3.88 ata. Next, convert absolute pressure to depth: hydrostatic pressure = 3.88 ata - 1.0 ata (surface pressure) = 2.88 atm. In seawater, 2.88 atm * 10 meters/atm = 28.8 meters (rounded to 29 meters or 95 feet).
7What is the partial pressure of nitrogen (PN2) for a diver breathing air (79% nitrogen) at a depth of 20.6 meters (68 feet) in fresh water?
A.1.58 ata
B.2.37 ata
C.1.97 ata
D.3.00 ata
Explanation: First, find absolute pressure in fresh water. Hydrostatic pressure increases by 1 atm every 10.3 meters (34 feet) in fresh water. At 20.6 meters, hydrostatic pressure is 20.6 / 10.3 = 2.0 atm. Absolute pressure = 2.0 atm + 1.0 atm (surface) = 3.0 ata. Using Dalton's Law, PN2 = 3.0 ata * 0.79 = 2.37 ata.
8An anchor weighs 150 kg on land and displaces 60 liters of water. How much force (negative buoyancy) is required to lift this anchor off the seabed in seawater?
A.90.0 kg
B.88.5 kg
C.91.5 kg
D.61.5 kg
Explanation: Archimedes' Principle states that the buoyant force equals the weight of the fluid displaced. The anchor displaces 60 liters of seawater, which weighs 60 liters * 1.025 kg/liter = 61.5 kg. The apparent underwater weight is land weight minus buoyant force: 150 kg - 61.5 kg = 88.5 kg. Therefore, a lifting force of 88.5 kg is required.
9A heavy equipment crate weighing 110 kg is placed in a freshwater lake. The crate displaces 120 liters of water. What is the buoyancy status of this crate?
A.It is positively buoyant by 10 kg and will float.
B.It is neutrally buoyant.
C.It is negatively buoyant by 10 kg and will sink.
D.It is positively buoyant by 13 kg and will float.
Explanation: The crate displaces 120 liters of freshwater, which weighs 120 kg (since freshwater density is 1.0 kg/liter). The buoyant force (120 kg upward) exceeds the crate's weight (110 kg downward). Therefore, the crate is positively buoyant by 120 kg - 110 kg = 10 kg and will float.
10A scuba cylinder is filled to 200 bar in a dive shop where the ambient temperature is 20°C (293 K). If the cylinder is left in a hot car where the temperature reaches 50°C (323 K), what will the pressure rise to (assuming cylinder volume is constant)?
A.230 bar
B.205 bar
C.220 bar
D.250 bar
Explanation: Charles's Law states that for a constant volume, pressure is directly proportional to absolute temperature (P1/T1 = P2/T2, with temperature in Kelvin). Here, P2 = P1 * (T2 / T1) = 200 bar * (323 K / 293 K) = 220.5 bar. This demonstrates the danger of exposing filled cylinders to high temperatures.

About the PADI Divemaster Theory Exam

The PADI Divemaster Dive Theory Examination evaluates a candidate's knowledge of the five key topics required of a professional dive leader. This exam tests deep understanding of diving physics (including buoyancy and gas behaviors under pressure), diving physiology (focusing on gas exchange, barotraumas, and decompression illnesses), scuba equipment mechanics and maintenance, decompression theory (relying on Haldanean models and the RDP/eRDPML), and dive safety, navigation, and environmental supervision.

Assessment

100 multiple-choice questions covering all five dive theory sections

Time Limit

2.5 hours

Passing Score

75%

Exam Fee

$150 (Professional Association of Diving Instructors (PADI))

PADI Divemaster Theory Exam Content Outline

20%

Physics of Diving

Liquid density, pressure measurements, gas laws (Boyle's, Dalton's, Henry's), light absorption, acoustics, and thermodynamics.

20%

Physiology of Diving

Anatomy of breathing, oxygen/nitrogen/carbon dioxide transport, decompression sickness (DCS), gas narcosis, and hypercapnia.

20%

Scuba Equipment

First and second stage regulators, scuba valves, SPGs, hydrostatic testing of cylinders, and dive computer algorithms.

20%

Decompression Theory and RDP

Haldane decompression models, tissue compartment half-times, M-values, surface intervals, and multi-level dive planning using RDP tables.

20%

Skills and Environment

Underwater navigation, search and recovery, tide cycles, current types, marine life interactions, and dive master emergency protocols.

How to Pass the PADI Divemaster Theory Exam

What You Need to Know

  • Passing score: 75%
  • Assessment: 100 multiple-choice questions covering all five dive theory sections
  • Time limit: 2.5 hours
  • Exam fee: $150

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

PADI Divemaster Theory Study Tips from Top Performers

1Practice pressure-to-volume calculations (Boyle's Law) and gas partial pressure calculations (Dalton's Law).
2Learn the difference between decompression sickness (DCS) and lung overexpansion injuries, including symptoms and first-aid protocols.
3Understand the mechanics of open-circuit demand valve regulators, including how first and second stages reduce tank pressure.
4Practice designing multi-level dive profiles using the eRDPML to minimize nitrogen loading.

Frequently Asked Questions

What is the PADI Divemaster Theory Exam?

It is a comprehensive assessment covering the theoretical foundations of recreational diving. Candidates must show proficiency in physics, physiology, equipment, decompression models, and safety skills to qualify as PADI professionals.

What is the passing score for the Divemaster Theory exam?

Candidates must achieve a passing score of at least 75% on each of the five sections of the examination to qualify.

Are calculators allowed in the exam?

Yes, basic non-programmable calculators and the PADI Recreational Dive Planner (RDP table or eRDPML) are permitted and required to solve physics and decompression problems.