Physics is one of the most important branches of science that has really made life easier, specifically the lives of scuba divers. The world of scuba diving is indebted to the magnificent discoveries in physics of diving, one of which is Dalton’s law.

Dalton’s law emphasizes on the importance of partial pressure and its use among scuba divers. Hence this law is also popularly known as Dalton law of partial pressure. This law is one of the most important gas laws that have been used in scuba diving. It sheds light on the basic assumption that when a container is filled with gaseous mixture its total pressure is equal to the sum of the partial pressure that each of the gases exerts in the container. Simply put if nitrogen and oxygen are present in a container, the total pressure that the container holds is equal to the sum when the partial pressure of the oxygen and the nitrogen are added.

Understanding Dalton’s law is particularly important not only in the day to day activities of human life but most importantly among scuba divers. It is not alien to all scuba divers that a gas tank can contain not just one gas but a mixture of gases that will help make the dive and staying underwater for a relatively longer period of time possible. Knowing these breathing gases can also help the divers appreciate the importance of Dalton’s law since these breathing gases play a vital role in making a subs dive a possibility.

Since it is not possible to make the supply of air available underwater during a scuba diving activity, these breathing gases has been used to compensate on the need for air. More often than not, breathing gases are mostly composed of oxygen gas mixed with other inert gas, which could be more than one depending on the intensity and the difficulty of the dive. The same breathing gases are also used to prevent the occurrence of decompression sickness as well as reducing the time for decompression stops. Likewise the chance of nitrogen narcosis is also reduced; hence it becomes extremely important to monitor the allowable partial pressure of each of the gases used for a safe dive. Following John Dalton law of partial pressures, this seemingly difficult task is made possible.

Oxygen, being the most important among the breathing gases is no doubt the most essential in human’s quest for survival. So it only makes sense that oxygen should be given ample attention in the mixture of breathing gases because it can determine the depth operating at maximum dive. However, oxygen gas is only useful up to a certain depth thus failure to recognize this will make the lives of the divers in great danger. For oxygen to be safe as a breathing gas for scuba divers it should maintain its partial pressure at about 16kPa or 0.16 bar. Anything that is lower than this will put the divers in a great danger of suffering from hypoxia, which could be deadly. It is also important to note that the oxygen’s safe partial pressure is also dependent on the time of exposure. Because when the partial pressure of oxygen is at its maximum and so with its exposure time, oxygen toxicity is likely to happen which could include seizure like that of epilepsy. Thus scuba experts and professionals have made used of oxygen analyzers in measuring the partial pressure of the gas in the mix. Some of the gases that are used in the mix are helium, nitrogen, neon, and hydrogen while argon, carbon dioxide, carbon monoxide, and hydrocarbons are not acceptable as breathing gases therefore should not be part of the mix.

There are truly amazing facts that any scuba diver can learn from this sport and recreational activity. There is no doubt that one of them is the Dalton’s law.