PADI Practice Test PDF (Free Printable 2026)

The padi certification program is the world's most widely recognized scuba diving training system, with more than 29 million certifications issued since the organization was founded in 1966. Whether you are just starting out with the entry-level Open Water Diver course or advancing toward a professional rating, the written knowledge development sections of each course include exam questions designed to verify that you understand the physics, physiology, and safety protocols that keep divers alive underwater. Studying those questions in advance — and understanding why each answer is correct — is one of the fastest ways to build real diving competence alongside your in-water skills.

This page provides a free printable PADI practice test PDF so you can review the core theory content away from a screen. The PDF covers topics drawn from the Open Water Diver curriculum and includes questions on buoyancy principles, gas laws, decompression safety, dive planning, and emergency procedures. Print it at home, work through it before your pool sessions, and use the answer key at the back to identify the areas that need more study before you sit your final knowledge review with your instructor.

What the PADI Open Water Diver Exam Covers

Buoyancy and Pressure Physics

Buoyancy control is the foundational skill of recreational diving and the written exam tests the physics behind it. Archimedes' principle states that an object immersed in a fluid experiences an upward buoyant force equal to the weight of the fluid it displaces. Divers use a buoyancy compensator device (BCD) to add or release air, fine-tuning displacement so they hover neutrally at any depth. Questions in this section ask you to calculate whether an object sinks, floats, or is neutrally buoyant based on its weight and volume compared to the surrounding water.

Boyle's Law governs how gas volume changes with pressure: as pressure doubles, volume halves, and vice versa. At 10 metres of sea water (msw) a diver experiences 2 bar of absolute pressure, so a lung full of air at the surface would compress to half its volume at that depth. This relationship explains why a diver must never hold their breath while ascending — expanding gas in the lungs can cause a pulmonary over-inflation injury. Exam questions often present a balloon or air space at one depth and ask you to calculate its new volume at a different depth using the Boyle's Law formula: P1 × V1 = P2 × V2.

Henry's Law explains why nitrogen dissolves into body tissues under pressure and comes back out of solution on ascent. The rate at which nitrogen is absorbed depends on depth, time, and the tissue compartment. Understanding this law is the foundation for everything that follows in decompression theory, and you can expect at least two or three exam questions that ask you to apply it to realistic dive scenarios.

Decompression Sickness and No-Decompression Limits

Decompression sickness (DCS) occurs when dissolved nitrogen forms bubbles in tissues or blood during an ascent that is too rapid. Symptoms range from joint pain and skin mottling (Type I) to neurological deficits, paralysis, or death (Type II). The exam tests your knowledge of the causes, signs, symptoms, first-aid steps (high-concentration oxygen, hydration, horizontal position, evacuation to a recompression chamber), and prevention strategies including slow ascents at 9 metres per minute and safety stops at 5 metres for 3 minutes at the end of every dive.

No-decompression limits (NDL) define the maximum time a diver can spend at a given depth on a single dive before a mandatory decompression stop is required. PADI recreational diver training uses dive tables and dive computers to track cumulative nitrogen loading across multiple dives. Exam questions ask you to use the Recreational Dive Planner (RDP) table to find NDLs for given depths, calculate surface intervals needed to reduce a pressure group, and plan repetitive dives safely. The ability to read and apply the RDP correctly is one of the most heavily tested skills in the Open Water written exam.

Equalization and Ear Health

Pressure increases rapidly in the first 10 metres of the water column, and the air spaces in the ears and sinuses must be equalized frequently during descent. The Valsalva maneuver — pinching the nose and gently exhaling — forces air through the Eustachian tubes into the middle ear. The Frenzel maneuver achieves the same effect using tongue and throat muscles instead of lung pressure, which many divers find easier and less likely to cause injury if performed too forcefully. Exam questions describe scenarios where a diver feels ear pain on descent and ask what the correct response is (stop, ascend slightly, equalize, then continue — or abort the dive if equalization fails).

Barotrauma of the ear, sinus squeeze, and mask squeeze are all covered in this section. The exam also includes questions on reverse squeeze, which can occur on ascent when congestion traps air in the middle ear, and on how conditions such as a cold or allergy affect a diver's ability to equalize safely. The rule that students must apply is straightforward: never force an equalization, and never dive with congestion that prevents equalization.

Dive Planning, Air Consumption, and Buddy Protocols

Every PADI dive begins with a pre-dive safety check using the BWRAF acronym: BCD, Weights, Releases, Air, Final check. The exam tests knowledge of this checklist and of the planning steps that precede it: checking the dive site, agreeing on a maximum depth and time, identifying entry and exit points, and establishing lost-diver procedures. Air consumption is quantified using Surface Air Consumption (SAC) rate — the volume of air consumed per minute at the surface — and Respiratory Minute Volume (RMV), which accounts for tank size. Exam questions ask students to calculate how long a given tank will last at a specific depth based on SAC rate and the pressure group at the start of the dive.

The buddy system is central to PADI training and the exam includes questions on buddy communication, the standard hand signals (OK, problem, go up, go down, low on air, out of air, look), and what to do when separated from a buddy underwater. A separated diver should search for one minute, then surface. Questions also cover the use of surface marker buoys (SMBs) for ascents when boat traffic is present, and tank bangers as an audible attention device. Marine life interaction rules — no touching, no feeding, maintaining buoyancy to avoid contact with the reef — appear in one or two questions in the environmental responsibility section.

Working through a printed practice test is one of the most efficient study methods for the PADI knowledge reviews because it forces active recall rather than passive reading. When you get a question wrong on paper, write a brief note next to it explaining the correct principle — that combination of retrieval failure and correction is the mechanism that drives long-term retention. Bring the annotated PDF to your pool sessions and review any flagged questions with your instructor before your open water dives. You can also explore the full padi certification practice test library on this site for additional timed quizzes organized by knowledge development section, which mirrors the exact structure of the PADI Open Water Diver course materials.