Independent course guide · References checked 30 September 2026. Confirm current standards and your eligibility with an authorised instructor.
Where this course fits
Advanced Nitrox, Decompression Procedures and substantial logged experience are part of the entry pathway; verify current standards.
Discuss recent technical dives, team procedures and the intended equipment before enrolling.
TDI Trimix Diver: learning scope
Entry & preparation
Advanced Nitrox, Decompression Procedures and substantial logged experience are part of the entry pathway; verify current standards.
What you study
Develop mixed-gas planning and execution for appropriately experienced technical divers.
- Oxygen, helium and nitrogen considerations
- Decompression and contingency planning
- Multi-gas team execution
Qualification boundary
Trimix qualification has defined limits and does not automatically cover hypoxic advanced trimix, caves or CCR.
A visual summary of this independent course guide. Confirm current prerequisites and standards with the agency and instructor.
What the training focuses on
| Learning area | Discuss before booking |
|---|---|
| Oxygen, helium and nitrogen considerations | How will this be taught and assessed? |
| Decompression and contingency planning | What preparation and equipment should I bring? |
| Multi-gas team execution | What happens if I need more practice? |
Understand the qualification’s scope
Trimix qualification has defined limits and does not automatically cover hypoxic advanced trimix, caves or CCR.
Frequently asked questions
Does helium remove all deep-diving risks?
No. Gas density, oxygen exposure, decompression, equipment and human factors still matter.
Is this an entry-level scuba course?
No. It requires prior technical competence and experience.
Does open-circuit Trimix qualify me on a rebreather?
No. CCR training is unit-specific and separately assessed.
What should an Australian course quote include?
Ask for an itemised total covering learning materials, practical sessions, certification, equipment, boat or site fees and any extra training. Availability, duration and prices are centre-specific.
Where do I confirm the latest prerequisites?
Use the official TDI information linked below and ask the authorised instructor to check your certification, age, experience, medical and first-aid records. A similar course name from another agency is not automatic equivalence.
Official course information
TDI: Trimix Diver ↗Agency standards determine certification requirements. This guide does not reproduce the full standard or imply agency endorsement.
Related next steps
Check prerequisites and readiness before choosing another course.