What is Technical Diving?

Here is a little overview of the differences between Recreational and Technical Diving – extreme diving..

Recreational (“Rec”) divers are trained (with Deep Specialty rating) to a max depth of 40 m, the worldwide maximum depth for non decompression diving. During Tec training however, this depth limit is increased based on the level of training being undertaken. The depth-based definition is derived from the fact that breathing regular air while experiencing pressures causes a progressively increasing amount of impairment due to “Nitrogen Narcosis”, a narcotic effect on the body caused by increased pressures of nitrogen within the diver’s tissues. This usually becomes apparent to the diver at depths of 30 meters (100 ft) or greater. Increasing pressure at depth also increases the risk of oxygen toxicity based on the partial pressure of oxygen in the breathing mixture. For this reason technical diving? often includes the use of breathing mixtures other than air.

DECOMPRESSION DIVING?:

While the Rec diver is solely trained for No-Decompression Diving (staying within limits governed by Recreational dive tables), the Tec diver will be trained to move outside of these limits. The purpose of decompression diving is to allow the diver to stay longer at depth and compensate for this by making predetermined “stops” during ascent to the surface. This allows inert gases in the body’s tissues (primarily Nitrogen) to be released slowly, thereby avoiding complications from Decompression Sickness, or “The bends”.

MIXED GAS DIVING/GAS SWITCHING?:

Rec divers use compressed air and some basic Nitrox mixes only. Tec divers also use these gases, but they may also use Nitrox with an oxygen content higher than the Rec limit of 40%. After further mixed gas training they are also able to use additional gas mixes containing other gases such as Helium or even Hydrogen, creating options such as Trimix, Heliox, Heliair and Hydrox. This type of diving requires extensive dive planning and gas management, but allows the diver to manage their gas intake before they even submerge. “Gas switching” means exactly that: the ability of a diver to switch between different breathing gases underwater. In Rec diving only a single gas is used, while for Tec diving the diver may switch between gases to accelerate decompression (shorten time required during stops) and/or “travel mixes” to permit descent carrying “hypoxic” gas mixes, or gases with an oxygen content too low to sustain life (e.g. 16% at the surface.)

WRECK DIVING?:

Rec divers can choose to complete the Wreck Diving specialty as basic wreck diving training. The difference between Rec and Tec wreck training lies in the ability to penetrate into the wreck structure itself – for Rec divers the penetration into an underwater wreck is limited to an area classed as the “light zone” or approximately 30 meters. The Tec diver, with appropriate training, is able to penetrate to any depth desired, and marker lines are reeled out to facilitate easy exits. Good buoyancy skills are also taught to ensure minimum amount of silt disturbance, which could lead to sharp drops in water clarity. This is also very similar to cave training.

CLOSED CIRCUIT REBREATHER DIVING?:

One of the highest levels of training involves Closed Circuit Rebreathers (“CCR’s” or “Rebreathers”), a unit coming slowly to the forefront of diving with the aid of modern technology. CCR’s, used primarily in the past by military and scientific sectors, work on the principle of recycling exhaled gas rather than letting bubbles simply vent into surrounding water. Due to the body metabolizing a certain percentage of the oxygen in the loop, oxygen is injected into the loop from a small tank attached to the machine. A “scrubber” canister chemically removes excess carbon dioxide from the exhaled mix to prevent CO2 buildup. These combine to create a unit that allows between three to five hours gas supply underwater irrespective of depth, thereby decreasing gas costs and tank carrying