100% CORRECT ANSWERS 2026
1. As a newly certified PADI Open Water Diver, I will be trained to dive with a
buddy as deep as:
a. 12 metres / 40 feet
b. 18 metres / 60 feet ✅
c. 30 metres / 100 feet
d. 40 metres / 130 feet
Rationale:
PADI Open Water Diver certification allows divers to safely dive with a buddy to a
maximum depth of 18 metres / 60 feet. This limit is set to reduce the risk of nitrogen
narcosis and decompression sickness, which are more likely at greater depths for
inexperienced divers. It also ensures divers are diving within the scope of training
provided in their course.
2. As you descend in water, the pressure:
a. decreases
b. stays the same
c. increases ✅
d. fluctuates
Rationale:
Water exerts pressure in all directions, and this pressure increases with depth.
Every 10 metres / 33 feet of seawater adds roughly 1 atmosphere (bar) of
pressure. This increase affects air spaces in the body and equipment, making
equalization and buoyancy control essential.
,3. A depth change of 10 metres / 33 feet causes a pressure change of:
a. 0.5 bar
b. 1 bar / ata ✅
c. 2 bar
d. 3 bar
Rationale:
At sea level, the pressure is 1 atmosphere (bar). For every 10 metres of seawater,
pressure increases by 1 bar, so a diver at 10 metres experiences 2 bar total
pressure. Understanding this principle is crucial for calculating air consumption and
avoiding barotrauma.
4. If you take 6 litres of air from the surface to 20 metres / 66 feet, the
volume will be:
a. 6 litres
b. 4 litres
c. 3 litres ✅
d. 2 litres
Rationale:
According to Boyle’s Law, the volume of a gas decreases as pressure increases. At
20 metres, the pressure is roughly 3 bar (1 bar surface + 2 bar water). Therefore, 6
litres of air at the surface would compress to 6 ÷ 3 = 2 litres. This demonstrates why
divers must monitor air supply carefully at depth.
5. A balloon fully inflated and sealed at 10 metres / 33 feet would probably
______ during ascent to the surface:
a. shrink
b. stay the same
c. burst ✅
d. float away
Rationale:
As a diver ascends, pressure decreases, and the gas inside the balloon expands
,according to Boyle’s Law. If the balloon is sealed, the expanding gas has nowhere to
escape, causing it to burst. This is a classic example of why divers must ascend
slowly and allow gases to expand safely in their body and equipment.
6. A squeeze is caused by:
a. cold water
b. a pressure imbalance between the surrounding pressure and an air space ✅
c. strong currents
d. excessive breathing
Rationale:
A squeeze occurs when the pressure in an enclosed air space, such as ears or
sinuses, is less than surrounding water pressure. This pressure imbalance can
cause pain and tissue damage. Equalization techniques are used to prevent this during
descent.
7. Equalization is the process of:
a. removing air from a wetsuit
b. ascending rapidly
c. adding air to an air space ✅
d. adjusting buoyancy
Rationale:
Equalization balances air pressure in body cavities with surrounding water
pressure. Common methods include gently blowing against pinched nostrils (Valsalva
maneuver). Proper equalization prevents ear and sinus injuries during descent.
, 8. The most important rule in scuba diving is to:
a. ascend rapidly
b. hold your breath
c. breathe continuously and never hold your breath ✅
d. swim fast
Rationale:
Holding your breath while ascending can cause lung overexpansion injuries due to
expanding air in the lungs. Continuous breathing allows air to escape safely,
preventing pulmonary barotrauma and serious injury.
9. During ascent, I feel discomfort in my ears. I should:
a. ignore it
b. ascend faster
c. stop, descend slightly, and allow trapped air to work its way out ✅
d. hold my breath
Rationale:
Discomfort during ascent is often due to trapped air in the middle ear. Descending
slightly allows pressure to equalize. Forcing ascent without equalization can cause
injury.
10. My buddy and I descend to 12 metres / 40 feet. I would expect to use my
air _____ at 6 metres / 20 feet:
a. slower
b. at the same rate
c. faster ✅
d. not at all
Rationale:
Air density increases with depth due to higher pressure, so more molecules of air
are inhaled per breath at greater depths. Therefore, a diver uses air faster at
deeper depths than shallower depths.