Trimix OC

The OC Trimix course is for divers who want to further their theoretical and practical training for project-related diving.

Training content

The Trimix course is an advanced training course for divers without a decompression limit. Divers must be able to safely complete decompression in open water with multiple faults under a time limit. They must stay within the planned runtime and solve all errors on the side.

During dive planning, the safety factors (GF factors) are set very conservatively, as the participants should learn to master problems and dive a self-created runtime cleanly.

The PO₂ of the base mixture must not exceed 1.4 bar for long immersion times and the decompression gases must not exceed 1.6 bar PO₂. The maximum permissible anesthetic depth should be between 3.2 and 3.6 bar PN₂.

If individual exercises are not satisfactorily mastered by the end of the course, the course can only be completed once these have been successfully carried out in further training dives.

Training objectives

  • Advanced trimix training with surface-breathable trimix mixtures
  • Problem solving – floating and ascending
  • Solving multiple errors with tight deadlines
  • Handling of 3 stage cylinders with trimix, nitrox and O2 gas exchange, incl. deco gas redundancy
  • Advanced deco training with oxygen, nitrox and trimix mixtures
  • Making training measurable
  • Advanced Deko TEC training
Limit after successful course completion
  • Maximum depth 75 meters
  • No limit on decompression times


At the start of the course:

  • Minimum age 21 years
  • Proof of health status, not older than 2 years
  • Proof i.a.c. Normoxic Trimix OC or comparable, according to current i.a.c. equivalence list
  • Electronic logbook proof of at least 150 dives, including 30 deco dives and 20 deeper than 40m

Here you become a TEC Trimix OC