What is the key characteristic of the pressure-volume relationship as defined by Boyle's Law?

The key characteristic of the pressure-volume relationship defined by Boyle's Law is that volume decreases as pressure increases when the temperature is kept constant. This inversely proportional relationship illustrates that if the pressure exerted on a gas is increased, the volume of that gas will decrease, provided the temperature remains unchanged. This principle is critical in various applications involving gas behavior under changing conditions, such as during diving when external pressure changes with depth.

Understanding this relationship is vital for dive supervisors as it relates to the behavior of gases in diving environments. The changes in pressure experienced underwater can affect gas volumes in divers' bodies and equipment, making it essential for safety and management during dives.

With regard to the context of the other provided choices, while temperature does need to remain constant in Boyle's Law, stating that pressure increases with volume is contrary to the fundamental understanding of this law. The idea of constant pressure while volume increases also contradicts Boyle's Law, as it specifically describes the inverse relationship between pressure and volume.