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.


GUE’s Closed-Circuit Rebreather Diver Level 1 course is intended for GUE Tech 1 divers who desire to learn to dive with a closed-circuit rebreather.

Tech 1 divers who aspire beyond their current level will find that this course gives them the tools to do so by building and enhancing their technical diving abilities.


Course outcomes include, but are not limited to: a competent and comfortable rebreather diver with solid personal and team skills; knowledge of rebreather functions, operation and how to act if experiencing failures; competent in performing bailout to open circuit, including ascent protocol; and can plan technical dive missions including, gas, absorbent canister endurance, oxygen toxicity management, and decompression strategies.
Prerequisites and Duration

Applicants for a GUE CCR Diver Level 1 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 Tech 1 course.
  • Must have a minimum of 25 logged Tech 1 level dives beyond GUE Tech 1 certification.
The Closed-Circuit Rebreather Diver Level 1 course is usually conducted in six days, requiring a minimum of seven dives, including two experience dives, as well as at least 48 hours of instruction, which includes classroom lectures, land drills and in-water work.