5 THINGS TECHNICAL DIVERS HAVE GIVEN US
WE ARE ALL INVOLVED in the same great sport. Whether you are a recently qualified open water diver or an experienced one who has dived the world, there is a bond that connects you. You are divers.
One of the most notable features of this bond, one that connects even the most occasional diver with the pioneers who push the frontiers of underwater exploration, is the way in which those at the cutting edge of the sport influence how the rest of the world dives.
Just as the technologies developed for racing cars eventually find their way into the family saloon – ABS braking, air-bags and push-button ignition, for example – so in recent years cave-, wreck- and technical divers have been responsible for significant developments in scuba equipment and diving practice, which have been passed on to the sport-diving community at large and which are now universally accepted.
1 ALTERNATIVE DIVING GASES
It’s hard to believe now, but not so long ago many of scuba’s most influential organisations and periodicals were forecasting that to introduce nitrox to recreational divers would lead to disaster.
They dubbed it the “devil gas” and forbade all exhibitors at dive shows from advertising anything to do with it. One major tourist destination, the Cayman Islands, initially issued an edict banning nitrox-diving from its waters completely.
However, technical-divers had been using higher oxygen mixes to extend bottom time and conduct safer decompressions for years and, in a demonstration of people power, divers all over the world decided that they would ignore the warnings of the conservative scuba establishment. They flocked to the technical training agencies to see for themselves what nitrox was all about.
This forced a dramatic about-turn from the mainstream organisations, which now of course espouse nitrox wholeheartedly, and even offer it as an option on beginner diver courses.
If in the early 1990s the sight of a diver with a nitrox tank raised hackles, in 2017 that green and yellow band won’t cause an eyebrow to be raised. Nitrox is everywhere.
Now there are signs of helium-based diving gases entering the mainstream. The use of breathing mixtures such as trimix, heliox and heliair has long been the province of ultra-deep divers, who use them as a bottom gas with low oxygen and nitrogen content to avoid oxygen toxicity and reduce narcosis at depth.
In recent years, however, technical divers have also been successfully using helium-based mixtures with higher O2 content for more shallow decompression dives, to offset the effects of narcosis.
This is especially important for rebreather divers, for whom the ability to focus and concentrate is critical. Some training agencies have even introduced single-cylinder, no-decompression stop, recreational diving courses on helium-based gas mixtures for divers wanting to reduce narcosis to the minimum.
There are still comparatively few helium-capable dive computers around but deco tables are available for common mixes such as trimix 32/15 (32% oxygen and 15% helium), which offers similar no-decompression times to nitrox 32.
If you get a chance, “try MIX”. The difference from diving on air is astonishing. You will find you are much more alert on your dives. You notice more of what’s going on around you, you are a more attentive buddy and you remember more about the dive afterwards.
2. LONGER REG HOSES
For decades divers carried only one second-stage regulator and learned to “buddy breathe” in an out-of-air emergency, with two people sharing a single second stage.
However, cave-divers trying to exit together following an air-supply crisis found it very difficult to buddy-breathe through narrow sections of a cave, (known as restrictions), and solved this problem by adding to their regulator set-up another second stage attached to a hose long enough to permit two divers following each other to breathe from the same cylinder.
Eventually this practice found its way out of the caves into mainstream diving, via the wreck-diving community. Air-sharing is much easier when each diver has his or her own second stage from which to breathe, and having a long hose for whoever is not carrying the air allows that diver to move freely beside the donor.
Having said this, while most divers today dive with two second stages, many now choose to have both of them attached to short hoses, which defeats the primary purpose of having two second stages.
Unless the hose on the regulator extended to an out-of-air diver is long enough to permit both divers freedom of movement, an air-sharing ascent in a genuine emergency is likely to be hard to accomplish without substantial stress.
3. SNAPS & D-RINGS
A key part of a technical diver’s configuration process is deciding where and how to stow equipment. Using snaps and D-rings allows accessories and hoses to be attached closely and securely and makes them much more accessible than if they are stowed away in a pouch with a variety of other items.
At depth, time is critical: gas supplies diminish fast and narcosis slows a diver’s speed of thought. For instance, the extra time taken to locate and deploy a cutting tool to extricate yourself from an entanglement emergency might make the difference between survival and failure.
Other advantages of keeping everything close and secured include the fact that a streamlined diver moves more quickly, wastes less energy and consumes less air, and a dangling hose or accessory can easily snag on a wreck or a coral-head, causing damage to both the equipment and the environment.
Divers noticed what the technical divers were doing and saw the practical value. Manufacturers took note of diver demand, and D-rings and snaps started appearing everywhere.
Not all the new products were an unqualified success. Some manufacturers just did not understand the concept. They added D-rings to loose chest straps that looked deceptively functional when the diver was standing up, but just allowed the objects attached to swing back and forth like miniature wrecking-balls when the diver was horizontal and swimming.
Others decided to economise and paint plastic D-rings silver, instead of using stainless steel. They just snapped when any pressure was applied to them.
Nevertheless, the overall trend has been positive, and divers of all levels are now able to set up their equipment much more efficiently and effectively than before.
The configuration revolution has yet to be universally adopted. You still see divers with hoses flying off them at all angles and accessories hanging pendulously from the end of extendable lanyards.
It would be good to see more emphasis on configuration in beginners’ courses.
Delayed surface markers buoys were initially popularised by technical divers, who use them as an aid to maintaining control of their depth during long drifting decompressions, and to enable the dive-boat to follow a diver or dive-team on a drifting decompression.
Divemasters all over the world saw the safety advantages of inflating and sending a buoy up from depth to identify the location of divers who were about to ascend. Now, beginner divers are also being taught how to raise a safety sausage from their safety stop.
This is a vital skill to have. It not only tells the pick-up boat where the divers are but it helps ensure that any other surface traffic in the area keeps clear.
If every diver on every dive ending in the open sea always came up under either their own SMB or someone else’s, scuba-diving’s safety record would improve enormously.
5. HARNESS & WING BC SYSTEMS
Like nitrox, harness and wing BC systems were another innovation that was developed by technical divers and initially greeted with disdain by the mainstream diving industry.
The objections came thick and fast. “They throw you onto your front at the surface” or “it’s difficult to vent air from them” were claims made by people who had never used them.
Of course, all that was required was that divers adapt their technique slightly. Then they could benefit from a design that holds a diver’s head higher on the surface, is easier to control than a wrap-around BC and doesn’t squeeze the rib-cage and inhibit breathing when inflated.
People liked the lack of encumbrance and freedom of movement permitted by having just a harness instead of an inflatable jacket around their torso.
They also liked how much easier it was to swim horizontally when their air-cell was all behind them.
As with nitrox, divers voted with their wallets and drove the change in the industry. Now most BC manufacturers offer harness and wing options, ever more divers are gravitating towards them and some new divers are even being taught to use this style of BC right from the start.
FAMOUS LAST WORDS
The way we dive has changed considerably in the past two decades, thanks in great part to the advances in technique and equipment made by those at the sharp end of the sport, those who continue to push the boundaries and draw us all behind in their wake.
To channel Monty Python, “yes,” you may say, “but, apart from nitrox, wings and harness BCs, octopuses, D-rings and helium, what have technical divers ever done for us?”
What indeed? Say thank you next time you see one.
Read more from Simon Pridmore in:
Scuba Confidential – An Insider’s Guide to Becoming a Better Diver
Scuba Professional – Insights into Sport Diver Training & Operations
Scuba Fundamentals – Start Diving the Right Way
All are available on Amazon in a variety of formats.