The TDI Advanced 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 (O2) mixtures during decompression to a maximum depth of 100 metres / 330 feet. The objective of the TDI Advanced Trimix course is to train divers in the benefits, hazards and proper procedures of utilizing custom oxygen / helium / nitrogen mixtures as breathing gases.

Qualifications of Graduates

Upon successful completion of this course, graduates may engage in technical diving activities utilizing custom trimix mixtures without direct supervision provided:

  • The diving activities approximate those of training
  • The area of activities approximates those of training
  • Environmental conditions approximate those of training

Open Water Execution

  • Four dives with a minimum accumulated bottom time of 100 minutes
  • At least 2 dives should be deeper than 70 metres / 230 feet

Course Structure

  • TDI allows instructors to structure courses according to the number of students participating and their skill level


  • The minimum number of classroom and briefing hours is 8.

Course prerequisites:

  • Minimum age 18
  • Minimum certification of TDI Extended Range or Trimix Diver or equivalent
  • Show proof of 100 logged dives, 25 must be deeper than 30metres/100feet

Contact us for more information