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The PADI Enriched Air Nitrox Specialty Course teaches certified divers to use air with added oxygen, up to 40%. Diving with this special mix allows for longer bottom times and safer diving. The course consists of academic learning, dive planning, and two open water dives, which can be done from our regularly scheduled dive trips. Divers learn to analyze the oxygen percentage in the tank before each dive.

Completing the course is easy and doesn't take much time! Once you learn about Nitrox, you'll see why it is so much safer and everyone is using it. The course has a book, 2 tables (formatted after the Open Water tables) and a 45 minute video that takes you through the course step by step. The class time is about 5 hours. You will go over the material you have read and watched in the video, take an exam and Ta Dan, you are ready to dive! All you need is a 2 tank dive on Nitrox and you are certified! It's that easy!!!!

The course prerequisite is 15 years old and Open Water Diver

Nitrox refers to any gas mixture composed (excluding trace gases) of nitrogen and oxygen; this includes normal air which is approximately 78% nitrogen and 21% oxygen, with around 1% other gases. The most common use of nitrox mixtures containing higher than normal levels of oxygen is in SCUBA diving where the reduced percentage of nitrogen is advantageous in reducing nitrogen take up in the body's tissues and so extending the possible dive time and/or reducing the risk of decompression sickness (also known as the bends).

Nitrox is mainly used in scuba diving to reduce the proportion of nitrogen in the breathing gas mixture. Reducing the proportion of nitrogen by increasing the proportion of oxygen reduces the risk of decompression sickness, allowing extended dive times without increasing the need for decompression stops. Nitrox is not a safer gas than compressed air in all respects: although its use reduces the risk of decompression sickness, it increases the risk of oxygen toxicity and fire, which are further discussed below.

It is generally untrue that breathing nitrox can reduce the effects of nitrogen narcosis, as oxygen seems to have equally narcotic properties under pressure; thus one should not expect a reduction in narcotic effects due only to the use of nitrox. For a reduction in narcotic effects Trimix gases which also contain helium are generally used.

There is anecdotal evidence that the use of nitrox reduces post-dive fatigue, particularly in older and or obese divers; however the only known double-blind study to test this found no statistically significant reduction in reported fatigue. There has, however, been some suggestion that post dive fatigue is due to sub-clinical decompression sickness (DCS) (i.e. micro bubbles in the blood insufficient to cause symptoms of DCS); the fact that the study mentioned was conducted in a dry chamber with an ideal decompression profile may have been sufficient to reduce sub-clinical DCS and prevent fatigue in both nitrox and air divers.

Further studies with a number of different dive profiles, and also different levels of exertion, would be necessary to fully investigate this issue. For example, there is much better scientific evidence that breathing high-oxygen gases increase exercise tolerance, during aerobic exertion. Though even moderate exertion while breathing from the regulator is a relatively uncommon occurrence in scuba, as divers usually try to minimize it in order to conserve gas, episodes of exertion while regulator-breathing do occasionally occur in sport diving. Examples are surface-swimming a distance to a boat or beach after surfacing, where residual "safety" cylinder gas is often used freely, since the remainder will be wasted anyway when the dive is completed. It is possible that these so-far un-studied situations have contributed to some of the positive reputation of nitrox.

In 1959 the United States Navy (USN) documented enriched oxygen gas procedures for the military use of what we today call nitrox, in the USN Diving Manual.

ving Center, began instituting diving procedures for oxygen-enriched air. He also developed a process for mixing oxygen and air which he called a continuous blending system. For many years Dr. Wells' invention was the only practical alternative to partial pressure blending. In 1979 NOAA published Wells' procedures for the scientific use of Nitrox in the NOAA Diving Manual.

In 1985 Dick Rutkowski, a former NOAA diving safety officer, formed IAND (International Association of Nitrox Divers) and began teaching nitrox use for recreational diving. This was considered heresy by some, and met with heavy skepticism by the diving community. In 1992 the name was changed to the International Association of Nitrox and Technical Divers (IANTD), the T being added when the European Association of Technical Divers (EATD) merged with IAND. In the early 1990s, the agencies teaching nitrox were not the main scuba agencies. New organizations, including Ed Betts' ANDI (American Nitrox Divers International), which invented the term "Safe Air" for marketing purposes, and Bret Gilliam's TDI (Technical Divers International) gave scientific credence to nitrox.

Meanwhile, diving stores were finding a purely economic reason to offer nitrox: not only was an entire new course and certification needed to use it, but instead of cheap or free tank fills with compressed air, dive shops found they could charge premium amounts of money for custom-gas blending of nitrox to their ordinary moderately experienced divers. With the new dive computers which could be programmed to allow for the longer bottom-times and shorter residual nitrogen times which nitrox gave

In 1970, Dr. Morgan Wells, who was the first director of the National Oceanographic and Atmospheric Administration (NOAA) Di, the incentive for the sport diver to use the gas increased. An intersection of economics and scientific validity had occurred. However, in the meantime during the early 90's, a number of feelings were hurt.

In 1996, the Professional Association of Diving Instructors (PADI) announced full educational support for nitrox. While other main line scuba organizations had announced their support of nitrox earlier, it was PADI's endorsement that put nitrox over the top as a standard sport diving "option."

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Neptune Dive Center and Fairtex Sport Club and Resort. 179/208, moo 5, North Pattaya Road, Pattaya (Naklua), 20150, Chonburi, Thailand.

Tel: 038-371141 Fax: 038-371446

Mobile: English, Nederlands, Deutsch. 086-1532636

Mobile: Thai 081-1509562

Email: info@diveneptune.com   scuba@tttmaxnet.com

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