Diving is an activity that appeals to a huge selection of people, and within diving, there are almost as many ways to enjoy the sport as there are participants. During the 1990s, scuba diving became a mass participation sport.
The increase in holidays to exotic destinations, together with a growing commercialisation of diver training agencies, combined to make it was possible for people to do a basic open water course in a few days during the annual summer holiday. Whole families could do an open water diving qualification, which allowed Mum, Dad and the kids to experience the wonders of the undersea world.
While the barriers to this underwater world were gradually being broken down, a small group of experienced divers were starting to push the limits of traditional recreational scuba diving. This movement, which has been christened ‘technical diving’, started off with just a few dedicated individuals. Over the last few years, this area has seen a huge increase in interest, and now a significant number of divers are moving towards technical diving. In this and subsequent articles, we will explore what is meant by technical diving, what is involved, the risks that arise and how you can move towards this type of diving.
For those who are not tempted to venture into this area of the sport, we will also discuss what lessons can be learnt from technical diving in order to improve normal recreational diving. This is similar to the way in which the majority of motorists will never come close to a Formula One Grand Prix car, but make use, in their own cars, of many of the innovations that have been developed by the Formula One teams.
In order to talk about technical diving, we should first try to define what is meant by the phrase technical diving. This is not as easy as it might seem. There is no agreed definition of the phrase, and different people use it to mean different things.
One common definition is that technical diving is everything beyond recreational diving. This is a good starting point but does have a few problems. First of all, different organisations have different limits for what constitutes recreational diving. For example, some organisations do not allow decompression diving within the limits of recreational diving whilst other organisations do. A second problem in defining technical diving as everything beyond recreational diving is that the dividing line between the two is not fixed. For example in the early 1980’s, Nitrox was considered to be firmly in the technical diving area. It was thought to be too risky for use by recreational divers. Yet over the last twenty years, Nitrox has become much more widely accepted, and today, when used correctly, is recognised as offering significant safety benefits for all divers.
Another definition is that technical diving is the type of diving that is at the leading edge of the sport, or the type of diving that is carried out by the pioneers. This is another appealing definition but suffers from some of the same problems as the previous ones. Where do we draw the line between the leading edge and mainstream but adventurous diving?
So, we can see that a firm definition of what constitutes technical diving is difficult to pin down. Despite this, it is usually easy to recognise it when we see it. Furthermore, it is clear that there are certain aspects that we can use to identify technical rather than recreational diving.
Dives to depths greater than those found in recreational diving, or involving significantly longer dive times, are typical in the field of technical diving. Dives are undertaken to considerably greater depths than the recreational limit of 40m. Depths of 50m to 100m are not uncommon, with many dives greater than 100m or even 200m. This inevitably means that technical diving is decompression diving. However, not all decompression diving is necessarily technical diving, as some recreational agencies do allow limited decompression.
In recreational diving, we often hear the term ‘no-decompression dive’. In reality, there is no such thing, as all dives require decompression to some extent. It may be that during the ascent, sufficient decompression occurs and no decompression stop is required, but we have still been decompressing during this ascent and will continue to decompress on the surface for a number of hours afterwards. This is why ascent rates and safety stops are essential, as they allow enough time to decompress during the ascent. So, rather than refer to a dive where we do not need to make mandatory decompression stops as a ‘no-deco’ dive, we can more accurately refer to it as a no-stop dive. Once we exceed the no-stop time, we cannot ascend directly to the surface without risking decompression illness.
Decompression stops are carried out at certain depths to allow the excess nitrogen in the body to reduce to a level where it is safe to continue on to the surface. Effective buoyancy control and the ability to hold decompression stops accurately are essential before any diver considers carrying out decompression diving.
With longer decompression times, it is common for technical divers to carry more than one breathing mix. In addition to back gas carried in large cylinders mounted—not surprisingly—on their back, they will also carry one or more deco gases. These are rich nitrox mixes, which will speed up the decompression. This is known as accelerated decompression and can make a significant difference to the amount of ...