GUE’s Closed-Circuit Rebreather Diver Level 2 course is intended to develop GUE CCR Level 1 skills by gradually building diver skill and knowledge regarding closed-circuit diving.

The course is also designed to extend diver capacity for challenges in a comfortable learning environment by emphasizing a higher degree of physical fitness, as well as a deeper understanding of the management, maintenance procedures, and protocols of the rebreather.


GUE’s Closed-Circuit Rebreather Diver Level 2 is intended for graduates of the GUE Closed-Circuit Rebreather Diver Level 1 course who wish to further their knowledge and understanding of advanced CCR diving in more demanding environments.

Students of this class wish to enhance their capacity of CCR diving within the GUE system.


Course outcomes include, but are not limited to: a competent and comfortable rebreather diver with solid personal and team skills, robust knowledge of rebreather functions, operation, and failures;  competent performing deep bailout to open circuit, including ascent protocol involving gas switches, rotations, and loss of decompression gases; and a diver that can plan aggressive technical dive missions including, gas, absorbent canister endurance, oxygen toxicity management and decompression strategies.

Applicants for a GUE CCR Diver Level 2 program must:

  • Be a minimum of 21 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 Closed-Circuit Rebreather Diver Level 1 course.
  • Have conducted a minimum of 50 closed-circuit rebreather dives beyond Closed-CircuitRebreather Diver Level 1 certification. A minimum of 25 closed-circuit rebreather dives must be deeper than 30 m.
  • Own their own GUE-approved closed-circuit rebreather.

The Closed-Circuit Rebreather Diver Level 2 course is normally conducted over six days. It requires a minimum of seven dives (including three experience dives) and at least 48 hours of instruction, encompassing classroom lectures, land drills, and in-water work.