Technical diving

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A technical diver with a sidemount configuration gets ready for a dive

Under technical diving (also technical diving , TecDiving, Tek-diving, Tec-Diving o. Ä.), Various forms of advanced scuba diving together, where additional or special diving equipment is used. The transitions from non-technical to technical diving are fluid and depend, among other things, on the diving organization involved . The techniques used come from professional and research diving , among others .

Definitions

Originally and from which it is named, technical diving referred to diving with one or more technical gases instead of compressed air as breathing gas . A technical gas is a process-technically obtained gas with defined purity requirements, which is necessary for the fundamental health suitability as breathing gas. Today there are different, differing definitions of technical diving, most of which have been specified by the various diving organizations .

On the one hand, diving with gases that are relatively easy to handle, such as nitrox, is no longer considered technical diving today . On the other hand, diving with compressed air is sometimes regarded as technical diving if there are significantly higher demands on technology and / or divers compared to simple no- stop diving with compressed air in open water, such as diving deeper caves or the planned exceeding of the no-decompression limit appropriate decompression phases under water.

Most diving organizations recommend that recreational divers do not exceed a depth of 40  meters . Only a few organizations allow recreational divers even 50 or 60 meters. All deeper dives are usually classified as technical diving.

equipment

In general, diving at greater depths brings with it four problems for the human organism, which can only be addressed with technical gases and the associated technical devices:

  • With increasing pressures at greater depths, the human blood absorbs a higher proportion of nitrogen , provided that this is present in the breathing gas. A higher proportion also leads to faster absorption. With increasing nitrogen partial pressure results in an increasing depth noise , which reduces the judgment and the reactivity and / or life-threatening euphoria leads.
  • An increased proportion of light gases such as nitrogen or helium in the blood, which occurs through prolonged inhalation of these gases under greater pressures (at corresponding depths), leads to volatilization when returning to lower pressures at lower depths . As a result, gas bubbles form in the blood, which, if you ascend too quickly or without decompression stops, damage the circulatory system ( decompression sickness ), which in extreme cases can be immediately fatal.
  • From a partial pressure of 1.6  bar, oxygen has a toxic effect on the human nervous system . With air (21% oxygen) as breathing gas, this occurs from 1.6 / 0.21 = 7.6 bar, which corresponds to a diving depth of 66 meters.
  • Below the atmospheric partial pressure of oxygen (0.21 bar), the uptake in the human lungs decreases sharply, which can lead to suffocation from 0.13 bar , and leads to a reduction in physical performance at 0.18 bar.

Basically, normal diving equipment is required for deep and long dives. However, this will be expanded and partially changed:

In some cases special gas mixtures are used, for example several breathing mixtures such as Trimix , Nitrox , Heliox and Hydreliox are used or different gas mixtures are used for different phases of the dive, such as travel mix, bottom gas (reduced oxygen content to avoid toxic partial pressure at great depths) and Deco Gas (increased oxygen content to shorten the decompression time at shallow depths, e.g. Nitrox50 for above 21 m). It should be noted that the mixtures, especially the bottom gas (for the deepest part of the dive), due to their low oxygen content, can no longer be breathed safely on the surface (approx. 16% oxygen).

In addition, you can choose between rebreathers - and mixed gas equipment consisting of a regulator and dive computer (special mixed gas computer ) for breathing equipment. Self-made or converted breathing masks are also used, as are simple devices for wet decompression .

Often, additional cylinders (stages) with different gas mixtures are used, e.g. B. cave diving .

In historical diving, helmet diving devices and hose devices are used. Special accessories are also wet, more rarely dry underwater vehicles (e.g. diving scooters , aquascooters or diving sleds ). For special dives, for example, guide lines are used - in cave diving and wreck diving and as safety lines in ice diving. Surveying equipment or search lines are of course also used in some cases for underwater use.

Remarks

  • Some diving destinations or diving areas, such as diving at great depths, caves or wrecks, are popular areas of technical diving due to the increased level of difficulty and the attraction of the particular.
  • The increased risks of some dives are minimized as far as possible through knowledge, experience, training, preparation and equipment. More attention is paid to the redundancy of vital equipment than in scuba diving . H. Most of the equipment ( diving equipment ) is available twice (or more than once ) and has been checked.

Individual evidence

  1. ↑ Cold water diving . Friday 8th November 2019
  2. ↑ Dive Leader. Do you want to extend your personal diving skills and plan and lead dives for others? British Sub-Aqua Club, accessed on March 1, 2019 (English): " The training also prepares you to dive to depths of up to 50 meters in a range of challenging conditions, following a series of post-qualification depth progression dives. "
  3. ↑ Plongée en bouteille. Plonger en bouteille et se former au sein de la FFESSM. Fédération française d'études et de sports sous-marins, accessed on March 1, 2019 (French): “ ... à partir de 18 ans: brevet plongeur level 3 (P3), autonomy à 60 m . "