Know More About Technical Diving by Max Walker
Continued from part 2
The basic course is named Advanced Nitrox Diver (IANTD) or Apprentice Tech Deep Diver (PADI). It teaches the student the benefits, hazards and proper procedures to dive to a 45m depth using high content oxygen for rapid decompression. This is deeper than the recreational diver’s limit. It is important to strictly follow the time and safety stops procedures for surfacing, otherwise decompression sickness (the Bends) could result. If a diver spends 30mins at a depth of 45m, they will need an extra 40minutes for decompression.
After finishing the basic course, the student can move on to the Technical Nitrox Diver (IANTD) or Tec-Deep Diver (PADI). In this course, the student dives as deep as 55 meters with two oxygen-rich tanks (one is pure oxygen) for decompression. The 30-minute deep dive practice at 55m will necessitate another 50 mins for decompression. Apart from the deep dive practice, the student thoroughly studies the high pressure impact on the diver and psychological changes and works on improving posture and buoyancy control technique.
The final course is Trimix Diver. The diver uses a combination of low oxygen, low nitrogen and high helium gas mixtures for an 80m dive. This gas mix is essential for such a deep dive as ordinary pressurized air places negative impacts on the diver’s body at depths of more than 55m. The 21% in air after 55m depth will cause the diver to conrulse and even lose consciousness - this is oxygen toxcity. Inappropriate usage of the trimix gases, however, will also cause problems; therefore, specialized training is a must. Next