Henry's Law (gas dissolution)

Henry’s Law states that gas dissolves into a liquid as pressure increases. This principle governs how much nitrogen enters your body during a dive.

When you descend to 30 m in Cebu, the ambient pressure is 4 bar. Because the pressure is higher than at the surface, more nitrogen moves from your regulator into your bloodstream. This process affects every diver because it dictates your nitrogen loading. If you ascend too fast, that dissolved gas forms bubbles in your tissues.

Watch your ascent rate carefully. I saw a student in Koh Tao in 2018 ignore his computer because he felt fine. He ignored the fact that gas stays in your blood until the pressure drops slowly enough for safe off-gassing. Always respect your dive computer’s ceiling. It tracks these physical changes in real time.