You may have heard about diving using enriched air nitrox, but what is it all about?
When we dive, we breathe from our regulator, which supplies gas at the ambient pressure of the surrounding water.
As we go deeper, the pressure increases. Gasses in contact with a liquid, dissolve into the liquid forming a solution, the greater the pressure the more gas dissolves into the liquid. If the pressure is reduced the gas diffuses back out of the liquid. A familiar example is a bottle of cola. The cola bottle is pressurized, and gas is held in solution in the cola. When you open the bottle the pressure is released and the gas is released I the form of bubbles. This is why your cola is fizzy. After a dive the reduction in pressure causes the risk of bubbles forming in your blood and tissues. These can cause blockages in your blood flow or put pressure on nerves. In diving this known as decompression sickness or the bends. Scuba diving has an impressive safety record, one that puts most other adventure sports to shame. A typical scuba dive is no more dangerous than a bus journey. But safety doesn’t happen by accident, always plan your dive and dive your plan.
In recreational diving, you to plan your dive within the no decompression limit (NDL). This means you can ascend to the surface in the event of a problem. To do this you use dive tables or dive computers. In recent years a number of smart phone aps have become available to help.
At shallower depths most divers will exhaust their air supply before decompression limits become a problem, but as you gain experience and start making deeper more challenging dives, the NDL starts to become the limiting factor.
The most widely used gas in diving is air. Air consists of approximately 21% oxygen 79% nitrogen. Oxygen is metabolized by the body, but nitrogen is not. During a dive nitrogen accumulates in the body tissues. On ascent it is this nitrogen being released from solution that can form bubbles and gives rise to the risk of decompression sickness.
Enriched air nitrox is air that has had some of the nitrogen replaced with oxygen. By reducing the nitrogen content safety is increased, as are allowable dive times. For example a dive to 30 meters on air is limited to 20 minutes using the PADI dive table. Using Enriched air with an oxygen content of 32% this increases to 30 minutes, allowing you more time to enjoy your dive.
You learn to plan recreational dives using nitrox on the PADI enriched air specialty course. In this short course, you will be shown how to analyze your gas, and calculate your NDL and maximum depth for your mix. This will allow you to get the maximum dive times in recreational diving.
DJL on Koh Lipe in Thailand can teach you to dive with nitrox, and can provide nitrox for diver’s qualified ad wishing to use it. Contact us today to book your next adventure.