The TDI Helitrox Course examines the theory, methods and procedures for planned stage decompression diving utilizing Helium in the breathing mixture.

This program is designed as a stand-alone course or it may be taught in conjunction with Advanced Nitrox.

The objective of this course is to train divers how to plan and conduct a standard staged decompression dive not exceeding a maximum depth of forty five (45) metres.

Students are permitted to utilize Enriched Air Nitrox and Helium mixes with no greater that 20% “He” content and up to 100% oxygen for decompression diving provided the gas mix is with their current certification level.

Breathing gas mixtures containing more than 20% Helium or less that 21% oxygen are not permitted.


  • At least 18 years of age
  • Advanced Open Water Diver certification (with Deep Speciality) or TDI Intro to Tech or equivalent
  • TDI Understanding Nitrox certification or equivalent
  • Show proof of fifty (50) logged dives

Course schedule:

  • Independent study online
  • One confined water training
  • Four (4) open water training dives with two (2) of those dives being deeper than 30 metres
  • If Advanced Nitrox is taught in conjunction with Helitrox, a minimum of six (6) dives are required

Training Material:

  • TDI Decompression Procedures Student Manual
  • TDI Extended Range / Trimix Student Manual