Entry Level Trimix Diver

Course Duration: 4 dives, 5 days

Classroom/briefings: Four dives with a minimum accumulated bottom time of 100 minutes, with at least two dives deeper than 130 fsw. Two dives may be credited from the Extended Range course or equivalent at the discretion of the instructor.


  • Minimum age of 18
  • Minimum certification as a TDI Advanced Nitrox Diver and Decompression Procedures diver or equivalent.
  • Proof of at least 100 logged dives


As your motivation to explore progresses you will find that you may want to go deeper to dive that wreck that is part of history or that cave system that you have read so much about. One of the major limiting factors of going deeper is narcosis; TDI’s Trimix Diver course shows how to minimize the effects of narcosis by adding helium to offset the nitrogen in your breathing gas. While taking the Trimix Diver course your TDI Instructor will teach you how to plan and execute dives utilizing as little as 18 percent oxygen and diving to maximum depth of 60 m/200 feet with a blend of helium appropriate for the planned depth.

The course covers topics and skills like:

  • Dive team planning
  • Dive team planning
  • Gas matching
  • Cylinder labeling
  • Surface marker deployment
  • Equipment configuration
  • Thermal protection options

The TDI Entry Level Trimix Course provides the training required to competently and safely utilize breathing gases containing helium for dives that require staged decompression, utilizing nitrox and/or oxygen mixtures during decompression to a maximum depth of 200 fsw.