SCUBA Crash Course

Everything you want to know about scuba

Synopsis of Gas Laws

Boyle's Law states that the volume and pressure are inversely related. Charles' Law says volume is directly related to temperature. Dalton's law states that the sum of a gas mixture equals the partial pressures of all the components in the mixture. Gay Lussac's law states that gas and pressure are directly related. Henry's Law says that the partial pressure of a gas is directly related to the amount of gas that dissolves in a liquid.

Scuba Conditions


You get the condition when you return to sea level after scuba diving too quickly, and nitrogen bubbles are released into your body, which blocks blood flow. Symptoms include dizziness, difficulty walking and/or talking, skin rash, tingling, and joint, leg, or arm pain. This condition is dangerous because serious cases result in coma or death, and at least half of the time the symptoms don't surface until an hour after the dive. It's treated usually by oxygen or IVs, and the sick person is put into a hyperbaric chamber to get re-adjusted to sea level pressure. Henry's Law relates perfectly to this condition. Because partial pressure is directly related to the amount of gas that will dissolve in a liquid, at a high pressure, like below sea level, the nitrogen bubbles won't dissolve into blood flow. You have to be aware of how this law works before scuba diving.

Air Embolisms

You can get air embolisms from surfacing from scuba diving too quickly or holding your breath for too long under water. Air bubbles emerge in blood vessels and block them. How dangerous the condition is depends on where the block happens; if a block happens in the coronary artery it might cause heart attack or irregular heartbeat. Some people are still left with brain damage even after treatment. Symptoms include a blue tone to skin, dizziness, loss of consciousness, chest pain, blurred vision, and low blood pressure. The most effective treatment is a hyperbaric chamber. Boyle's law comes into play here because as pressure decreases when a diver comes to the surface, volume increases and if the lungs cannot take the extra volume of air, it gets forced into the bloodstream as air bubbles.

Oxygen Toxicity

You get oxygen toxicity by being exposed to oxygen at high pressures. There are two different kinds of oxygen toxicity, CNS (central nervous system) and Pulmonary Barotrauma. Symptoms include feeling disorientated, vision problems, and breathing problems. Oxygen toxicity can result in convulsion, and if this happens while diving it often ends in drowning. This condition is dangerous because it can cause serious and un-repairable damage it your nervous system and can ultimately result in death. The best way to treat it is to remove pure oxygen at the first warning sign of oxygen toxicity, but a hyperbaric chamber is also used. Dalton's Law applies to this because the partial pressure of all the gases increases in the same ratio as the total pressure. Therefore, this law lets divers calculate the effects of oxygen at different pressures and depths to avoid oxygen toxicity and other diving diseases.

What is decompression sickness?