PADI Divemaster Certification Practice Exam

What happens to air in a flexible container when taken from 0 metres to 10 metres of seawater?

1. It expands fully

2. It compresses completely

3. It stays the same

4. The volume is reduced by half

The correct answer is: The volume is reduced by half

When air in a flexible container is taken from 0 meters to 10 meters of seawater, the pressure surrounding the container increases due to the weight of the water above it. According to Boyle's Law, which states that the volume of a gas is inversely proportional to the pressure exerted on it, as the pressure increases, the volume of the gas decreases. At sea level (0 meters), the pressure is approximately 1 atmosphere (atm). As you descend to 10 meters underwater, the pressure increases to around 2 atmospheres (1 atm from the atmosphere above and 1 atm from the water). Consequently, if the volume of air is reduced by half, it demonstrates the relationship defined by Boyle's Law. Therefore, the correct conclusion is that the volume of air in the flexible container is indeed reduced, reflecting the halving effect. Understanding this principle is crucial for practical diving applications, as it influences buoyancy and volume calculations for divers and equipment.