Advanced underwater missions beyond 50 m/170 ft require a robust skillset, extensive experience and in-depth knowledge, as well as resilience to handle potential difficulties at greater depths. These dives can be exciting, as many of the undiscovered and unexplored areas are beyond the limits of recreational or even level 1 technical diving limits.

Being proficient with dives at these depths will open the doors to project diving, exploration, and discoveries even further for all those who want to accept the challenge.


GUE’s Technical Diver 2 course is designed to enhance deep diving proficiency while using helium breathing gases and oxygen-enriched decompression gases.

It is a rigorous class designed to prepare divers for depths of 75 m/246 ft and beyond, using multiple (three or more) stages or decompression gasses, to manage their gas, bottom time, and decompression exposure in a safe and comfortable manner.


Course outcomes include, but are not limited to: the use of multiple stages; the use of trimix with greater percentages of helium; the use of hypoxic gas mixtures protocols; gas management; oxygen management; extended decompression; accelerated, omitted, and general decompression strategies; dive planning; and management of multiple cylinders.

Applicants for a GUE Technical Diver Level 2 program must:

  • Be a minimum of 18 years of age.
  • Be physically and mentally fit.
  • Be a non-smoker.
  • Be able to swim.
  • Obtain a physician’s prior written authorization for use of prescription drugs, except for birth control, or for any medical condition that may pose a risk while diving.
  • Have passed the GUE Tech 1 course.
  • Must have a minimum of 25 logged Tech 1 level dives beyond GUE Tech 1 certification.
  • Have logged 50 dives in a double tank configuration.
  • For a full list of course prerequisites, click here.
The Technical Diver Level 2 course is normally conducted over six days. It requires a minimum of seven dives (including three trimix experience dives) and at least 48 hours of instruction, encompassing classroom lectures, land drills and in-water work.



Being a GUE diver very often means being part of the team on a diving project. One of the responsibilities of good project team members is the ability to support logistics and have skills allowing them to prepare breathing mixes for their diving teams.

GUE’s Gas Blender course is designed to introduce the essential skills required to prepare diving breathing mixtures with emphasis on preparation of GUE standard gases.  


GUE’s Closed-Circuit Rebreather Diver Level 1 course is intended to provide the opportunity for divers to gradually transition from open circuit diving to closed-circuit diving.

The course is intended to challenge divers in a comfortable environment that emphasizes the need for learning management, maintenance procedures, and protocols of the closed-circuit rebreather. The course also emphasizes the need for increased physical and mental fitness.