Boyle's Law & Lung Volume: Calculating Compression at Depth

Boyle's Law: At constant temperature, gas volume is inversely proportional to pressure (P₁V₁ = P₂V₂).

Scenario

• Surface: P₁ = 1 atm, V₁ = 0.5 L (lung volume)
• Depth (2 atm): P₂ = 2 atm

Calculation

V₂ = (P₁V₁) / P₂ = (1 atm × 0.5 L) / 2 atm = 0.25 L

Diving Context

At 10 meters (33 ft) seawater, pressure doubles. A breath-held descent to this depth halves lung volume. This is why never hold your breath while ascending—expanding air can cause pulmonary barotrauma. Scuba regulators deliver air at ambient pressure, preventing compression.