NITROX

For those of you aspiring to get something more out of your diving, whether it be increased bottom time, or just the fact that you like the challenge of more 'technical' diving. This course is an ideal entry into the more technical side of Enriched Air Nitrox

NSC & EANx

NSC is able offer the following:

• Enriched Air gas blending
• Enriched Air equipment servicing and preparation (including the ability to service and prepare for pure oxygen.)
• Enriched Air instructing. We are able to offer a suite of courses to allow divers to pick what level of Enriched Air they want.

EANx DESCRIBED

Without making it too complicated the use of Enriched Air means that divers can safely extend their NDL times.

Enriched Air Nitrox (EANx) or Nitrox as it is sometimes referred to is a gas mix which contains an oxygen content greater than 21%, This means that with a higher percentage of oxygen in your tank there is a corresponding decrease in the % of nitrogen in the gas you breathe.

This means that during a dive you absorb less nitrogen than you would if you were breathing normal air, which results in longer NDL times.

The figures below show the time gains that can be made when using a 32% oxygen mix and a 36% oxygen mix.

Enriched Air diving is not however a new thing, it has been around for decades and has an impressive safety record, as long as a few simple rules are followed. These mainly concern the depth to which a particular mix can be used and time exposures to elevated concentrations of oxygen.

It would not be fair to promote the use of Enriched Air without also considering some of the drawbacks to its use and if you decide to join the Enriched Air course you'll soon learn that you 'don't get something (longer NDL's) for nothing'.

Without going into too much detail, equipment has to be compatible for use with higher concentrations of oxygen and may require modifications according to manufacturer's guidelines.

Cylinders MUST be oxygen clean and marked accordingly, and these MUST never be used with air from a normal compressor thereafter, otherwise the cylinders may become contaminated with oil and have to be recleaned before use with Enriched Air, and the consequences of filling a contaminated cylinder with Nitrox could be very serious. A dedicated cylinder avoids this problem but the costs of all the above have to be considered - renting a cylinder may be a cheaper alternative. Enriched air fills will also cost more than a normal air fill.

John Narey.