From recreational to technical diving
TDI Advanced Nitrox is where technical diving training usually starts. You learn to use nitrox mixes from 21 to 100% oxygen safely and to choose the best mix for dives to 40 metres. The right mix extends your time at depth without staged decompression, and oxygen-rich mixes will later become your decompression gases.
The course covers dives that need no staged decompression and prepares you for the TDI Decompression Procedures and TDI Extended Range courses.
What you learn
- Physiology: hypoxia, oxygen toxicity (central nervous system and whole body), nitrogen narcosis, nitrogen uptake and elimination, carbon dioxide and carbon monoxide hazards.
- Calculations: best mix and maximum operating depth (MOD), equivalent air depth, CNS loading for every dive.
- Equipment: what changes above 40% oxygen, cylinder labelling, preparing equipment for oxygen service, calibrating and using an oxygen analyser.
- Decompression: the benefits of EAN50, EAN80 and pure oxygen, the pros and cons of multiple gas switches.
- Gas blending: the instructor demonstrates one blending method.
Practice in the water
You make four open-water dives with at least 100 minutes underwater in total. Before every dive you run the START check and plan by gas consumption, oxygen and nitrogen limits. In the water you practise:
- buoyancy without moving your hands or feet, and a horizontal body position;
- handling a free flow from the primary regulator, shutting the valve and switching to the backup regulator;
- sharing air with your buddy as both donor and recipient;
- a safety stop and recognising stress in yourself and your buddy.
The course ends with a written exam.
Frequently asked questions
How is Advanced Nitrox different from a regular nitrox course?
A nitrox course teaches mixes up to 40% oxygen. Advanced Nitrox covers the whole range from 21 to 100% oxygen, equipment for oxygen service and the use of mixes for decompression.
Are there decompression dives in this course?
No. Advanced Nitrox is for dives without staged decompression. Planned decompression dives are taught in the TDI Decompression Procedures course.
How long does the course take?
5–7 days: theory, the exam and four open-water dives. We agree the schedule with you.
Do I need my own equipment?
No. We provide all the diving equipment for the course and the cylinders with nitrox mixes.