Nitrox and Air
The PADI Enriched Air Diver course teaches you the theory and skills necessary for diving with enriched air respectively Nitrox. What is Nitrox or enriched air and what are the benefits and advantages over “normal” diving with air? Let’s start with the first question. Basically Nitrox refers to any gas mixture composed of nitrogen and oxygen. The usual air we breathe is made up of about 21 % oxygen, 78 % nitrogen and about 1 % of other minor gases. As oxygen and nitrogen are the main constituents of normal air, air can also be understood as a Nitrox gas mixture. However in scuba diving the term is mainly used for nitrogen-oxygen gas blends with a higher percentage of oxygen than air. Common Nitrox blends are EANX32 (32% oxygen) and EANX36 (36% oxygen). Blends with an oxygen percentage over 40% aren’t used in recreational scuba diving, due to their special equipment requirements and shallower depth limits.
Nitrox for what: The problem with oxygen!
You may think that the benefits of Nitrox are based on the higher percentage of oxygen in your tank. Not least oxygen is the gas our body needs to produce energy and without oxygen most living beings of our earth would die (yes, even plants need oxygen to survive). However oxygen in high concentrations can also be quite hostile to life. Oxygen is in fact a high reactive gas and in high concentrations is toxic to most organisms. This is especially a concern for scuba divers as the partial pressure of oxygen rises as we go deeper. With normal air (21 % oxygen) it’s possible to go as deep as 54 meters before the oxygen concentrations become toxic to our body (though at that depth, nitrogen becomes a serious danger). However as we dive with Nitrox, the depth limits become shallower the higher the oxygen concentration becomes. During your Enriched Air Diver course you will learn how to calculate the depth limits for different Nitrox blends. Diving with Nitrox 36 for instance, limits our maximum depth to about 29 meters (oxygen partial pressure limit 1.4 bar). Thus high oxygen concentrations aren’t suitable for deeper diving.
The benefits of Nitrox: Less nitrogen!
If Nitrox just allows us shallower diving, then use it for what? Actually we don’t dive with enriched air because of the higher oxygen concentrations. We dive with Nitrox to reduce the nitrogen percentage of the gas blend we dive with. If we use EANX36 for instance, the nitrogen concentration will be reduced from 78% (air) to approximately 64%. As we learned during our Open Water Diver course long exposure to high concentrations of nitrogen raises the risk of
nitrogen narcosis underwater and decompression sickness once we ascended. As we go deeper, the partial pressure of nitrogen raises and more and more nitrogen dissolves into our bloodstream and body tissues. With Nitrox however we breathe lower concentrations of nitrogen which result in less nitrogen dissolving into our body tissues. Lower nitrogen intake translates again into longer no decompression limits. A dive to 30 meters with air for instance gives us a no decompression limit of only 20 minutes. If we use Nitrox 36 however the decompression limit extends to 35 minutes. Thus Nitrox allows us to dive longer at certain depths without increasing the risk of nitrogen narcosis and decompression sickness. Especially for multiple diving during several days, the benefits of enriched air are obvious. People usually report to be less tried and less exhausted after diving with Nitrox instead of air.
What you will learn during your Nitrox course
The PADI Enriched Air Diver course teaches you all the basics you need to know about diving with Nitrox. You will learn about the effect of Nitrox on your body and which guidelines and procedures to follow to guarantee safe diving. After the course you will be able to calculate the depth limits for specific Nitrox blends and use an analyzer to check the oxygen concentration of your enriched air cylinder. You will also be able to set a dive computer to specific Nitrox blends and oxygen partial pressure limits.
The course consists of a theory part and a practical session on the boat. After you read the theory and completed the final exam, you will be ready for one day on the boat, where you will complete two open water dive with Nitrox.
Minimum age: 12 years
Maximal group size per session: 8 students
Course duration: Half-day for theory and one day on the boat.
Course price: 6’800 baht (including daytrip to Pattaya) or 4’000 baht plus any dive trip of your choice.