PADI
Open Water Diver Final Assessment 2026–2027 | Practice Questions,
Answers & Detailed Rationales | Scuba Certification Exam Prep
This Study Guide Includes
➢ PADI Open Water Diver final assessment practice questions
➢ Answers with detailed rationales
➢ Scuba diving physics and pressure relationships
, PADI Open Water Diver Final Assessment
2026–2027 | Practice Questions, Answers &
Detailed Rationales | Scuba Certification Exam
Prep
1. If an object is neutrally buoyant in fresh water, the same object
placed into salt water would....
• A) Sink
• B) Float
• C) Remain neutrally buoyant
• D) Become negatively buoyant
Answer: B) Float
Rationale: Salt water is denser than fresh water because it contains
dissolved salts. An object that is neutrally buoyant in fresh water will
displace the same volume of salt water, but the salt water weighs
more. This increased buoyant force causes the object to float in salt
water.
2. I blow up a balloon, tie it off, and take it to the bottom of the
swimming pool. What will happen to the balloon and the air inside it?
,• A) The balloon will get smaller and the air inside the balloon will be
more dense
• B) The balloon will get larger and the air inside will be less dense
• C) The balloon will stay the same size and the air will remain the
same density
• D) The balloon will get smaller and the air inside will be less dense
Answer: A) The balloon will get smaller and the air inside the balloon
will be more dense
Rationale: As depth increases, pressure increases (by 1 atm for every
10m/33ft of seawater). According to Boyle's Law, as pressure increases,
the volume of a gas decreases. The balloon gets smaller, and since the
same amount of air is compressed into a smaller space, its density
increases.
3. I turn a glass upside down, trap the air in it by putting it in water,
and then I take the glass down to 10m/33 ft. The air space would...
• A) Become half the size it was at the surface
• B) Become one-third the size it was at the surface
• C) Stay the same size
• D) Become twice the size it was at the surface
Answer: A) Become half the size it was at the surface
, Rationale: At the surface, pressure is 1 atm. At 10m/33ft in seawater,
the pressure is 2 atm (1 atm atmospheric + 1 atm water). According to
Boyle's Law (P₁V₁ = P₂V₂), if pressure doubles, volume is halved.
Therefore, the air space becomes half its original size.
4. If I am not able to equalize my body air spaces, it may be because I
have...
• A) A cold, allergy or another medical problem
• B) Been diving too deep
• C) Not drunk enough water
• D) Been diving too long
Answer: A) A cold, allergy or another medical problem
Rationale: Colds, allergies, and other medical conditions cause
inflammation and congestion in the Eustachian tubes and sinuses,
making it difficult or impossible to equalize pressure in those air spaces.
Diving with these conditions can lead to barotrauma.
5. If my ears or sinuses hurt while I am descending, it usually means...
• A) I am feeling a squeeze and need to equalize
• B) I have decompression sickness
• C) I am ascending too quickly
Open Water Diver Final Assessment 2026–2027 | Practice Questions,
Answers & Detailed Rationales | Scuba Certification Exam Prep
This Study Guide Includes
➢ PADI Open Water Diver final assessment practice questions
➢ Answers with detailed rationales
➢ Scuba diving physics and pressure relationships
, PADI Open Water Diver Final Assessment
2026–2027 | Practice Questions, Answers &
Detailed Rationales | Scuba Certification Exam
Prep
1. If an object is neutrally buoyant in fresh water, the same object
placed into salt water would....
• A) Sink
• B) Float
• C) Remain neutrally buoyant
• D) Become negatively buoyant
Answer: B) Float
Rationale: Salt water is denser than fresh water because it contains
dissolved salts. An object that is neutrally buoyant in fresh water will
displace the same volume of salt water, but the salt water weighs
more. This increased buoyant force causes the object to float in salt
water.
2. I blow up a balloon, tie it off, and take it to the bottom of the
swimming pool. What will happen to the balloon and the air inside it?
,• A) The balloon will get smaller and the air inside the balloon will be
more dense
• B) The balloon will get larger and the air inside will be less dense
• C) The balloon will stay the same size and the air will remain the
same density
• D) The balloon will get smaller and the air inside will be less dense
Answer: A) The balloon will get smaller and the air inside the balloon
will be more dense
Rationale: As depth increases, pressure increases (by 1 atm for every
10m/33ft of seawater). According to Boyle's Law, as pressure increases,
the volume of a gas decreases. The balloon gets smaller, and since the
same amount of air is compressed into a smaller space, its density
increases.
3. I turn a glass upside down, trap the air in it by putting it in water,
and then I take the glass down to 10m/33 ft. The air space would...
• A) Become half the size it was at the surface
• B) Become one-third the size it was at the surface
• C) Stay the same size
• D) Become twice the size it was at the surface
Answer: A) Become half the size it was at the surface
, Rationale: At the surface, pressure is 1 atm. At 10m/33ft in seawater,
the pressure is 2 atm (1 atm atmospheric + 1 atm water). According to
Boyle's Law (P₁V₁ = P₂V₂), if pressure doubles, volume is halved.
Therefore, the air space becomes half its original size.
4. If I am not able to equalize my body air spaces, it may be because I
have...
• A) A cold, allergy or another medical problem
• B) Been diving too deep
• C) Not drunk enough water
• D) Been diving too long
Answer: A) A cold, allergy or another medical problem
Rationale: Colds, allergies, and other medical conditions cause
inflammation and congestion in the Eustachian tubes and sinuses,
making it difficult or impossible to equalize pressure in those air spaces.
Diving with these conditions can lead to barotrauma.
5. If my ears or sinuses hurt while I am descending, it usually means...
• A) I am feeling a squeeze and need to equalize
• B) I have decompression sickness
• C) I am ascending too quickly
