TDI Helitrox Diver
Reduce narcosis, extend your capability, and take your next step into mixed gas technical diving
Overview
The TDI Helitrox Diver course trains divers to plan and conduct staged decompression dives using helium-based breathing mixtures.
This programme builds directly on decompression procedures by introducing helium into the breathing gas, reducing narcosis and improving clarity at depth. Divers learn to manage mixed gases containing 21% oxygen with up to 35% helium, along with oxygen-rich decompression gases.
All dives are conducted within a maximum depth of 45 metres, focusing on controlled decompression, gas switching, and precise execution. At N9BO℠, this course represents the transition from air-based technical diving to true mixed gas operations.
Course Facts
- Course name: TDI Helitrox Diver
- Level: Technical mixed gas decompression course
- Minimum prerequisites: Minimum age 18, TDI Advanced Nitrox Diver or equivalent, TDI Decompression Procedures Diver or equivalent, minimum 25 logged dives
- Ratio: Maximum of 4 students per instructor (small groups recommended for quality training)
- Configuration: Technical configuration (backmount doubles or sidemount) with stage/decompression cylinders and helium-based bottom gas
- Depth / environment: Maximum 45m / 150ft with mandatory staged decompression
- Format: Academic development + confined/open water skills + and staged decompression dives using mixed gases
- Duration: Typically completed in 4 days (Minimum 4 decompression dives)
What You’ll Learn
- Plan and execute decompression dives using helitrox mixtures.
- Manage narcosis through the controlled use of helium.
- Use multiple gases including helium mixes and high-oxygen decompression gases.
- Execute complex ascent profiles with staged decompression.
- Apply advanced contingency planning and failure management.
Prerequisites
- Be at least 18 years old.
- Hold certifications in Advanced Nitrox and Decompression Procedures (or equivalent).
- Provide proof of at least 25 logged dives.
- Be medically fit for diving.
FAQ
This course is for technical divers who want to reduce narcosis and begin using helium in their diving, while staying within moderate technical depths.
Helitrox is a trimix-based breathing gas that contains oxygen (21%), helium (typically 20–35%), and the remainder nitrogen. By replacing part of the nitrogen with helium, helitrox significantly reduces narcosis while keeping oxygen levels at a standard 21%, making it an effective and accessible entry point into mixed gas diving.
You will complete four staged decompression dives using helium-based gas mixtures, focusing on gas switching, decompression execution, and precise dive control.
Helitrox builds on decompression training by adding helium to the breathing mix, reducing narcosis and improving diver performance at depth.
You will be qualified to conduct decompression dives using helitrox mixtures to a maximum depth of 45 metres, within conditions similar to training.
Ready to Dive Mixed Gas?
Send us your certifications and experience. We’ll help you transition into helium-based diving with the right structure and progression.
Go Pro with TDI Helitrox Instructor
Take your mixed gas diving to the professional level and start teaching helium-based decompression diving. Delivered by a TDI Instructor Trainer, this pathway builds the precision, control, and instructional ability required to train divers safely in helitrox procedures.
