IANTD Open Water Diver Practice Exam

The correct answer is Boyle's law, which states that the pressure exerted by a gas is inversely proportional to its volume when the temperature is held constant. This means that as a diver descends and experiences an increase in water pressure, the volume of any gas in a closed space will decrease.

Squeezes occur when the surrounding pressure increases but the volume of air in a space (like sinuses or ears) does not equalize, leading to discomfort or injury. For instance, if a diver descends without equalizing the pressure in their ears, the external water pressure increases, causing the air volume in the ears to compress, resulting in a squeeze.

Understanding Boyle's law is essential for divers because it helps them recognize the importance of equalization techniques during descent to prevent these issues and ensure safe diving practices.