Advanced Nitrox Diving.

Mar 21 2018 Posted by Office Administraton


Sheephaven divers took the opportunity over the Bank Holiday weekend to increase their diving skills by completing an Advanced Nitrox course with Barry Mc Gill.

Club members, Peter Druce, Kiaran Doherty, Ciaran Mc Glynn and Ryan Ward took their first steps towards decompression diving with a series of lectures and dives over the weekend, commencing on Saturday at the clubhouse in Downings.

The morning was given over to a combination of theory and practical demonstration of kit configuration.

In the afternoon the four candidates and their instructor conducted a shore dive at Massmount, to practice what they had been shown earlier.

Unfortunately in-water visibility at this location was very poor, but nonetheless they carried out their bubble checks, S-drill for their extended main regulator hose and gas switching from travel gas to deco gas drills.

Finally prior to their ascent the divers demonstrated to their instructor their stage bottle removal drill.

The divers were back in Downings for Sunday morning, where they conducted a boat dive to inside the Werrymen, thanks to Noel Brennan who provided Dry Coxswain duties.

This dive was to 16 metres in outstanding in-water visibility of at least 30 metres horizontally, with a 45 minute surface to surface time in water temperatures of 7 degrees Celsius and once again the divers went through their drills to the satisfaction of their instructor.

On Monday the divers returned to Downings once more for two more boat dives, but this time they were given the added challenge of diving with a ‘blacked out’ mask.

From a distance of 10 metres apart the ‘blacked out’ diver indicated to their buddy that they had an ‘air out’ situation and followed a pre-set line to their buddy, received their main regulator and buddy breathed back to the point of origin.

Once they had settled down the divers changed places and the other diver repeated the exercise.

This is a highly challenging exercise and it was subsequently followed with in-water cylinder shutdown on a 15lt bottle that utilises a Y-pillar valve, first shutting down the main regulator, followed by shutting down the octopus regulator and they are re-activated again in sequence -another very challenging exercise to be performed underwater.

Initially prior to their ascent the all divers deployed their Surface Marker Buoys to their instructors’ satisfaction.

The final dive was again to 16 metres but this time had a total surface to surface time of 64 minutes in water temperatures of 7 degrees Celsius.

Prior to all dives the divers blended their air mixtures, then analysed the cylinder contents and finally calculating the Maximum Operating Depth for that mix.

The general feedback of the weekends training was that it was highly demanding but very fulfilling and the divers are now confident that the have skills necessary to conduct decompression diving in accordance with the Irish Underwater Council cross equivalent grade for this course. Well done to all involved.