Hawaii SCUBA University Technical Diving Program – Closed Circuit Rebreather Training in Oahu Hawaii

Hawaii SCUBA University Technical Diving Program

(Closed Circuit Rebreather Training)

Aloha and welcome to the Hawaii SCUBA University(HSU) Technical Diving Program. This post is designed to give you a basic understanding of what and how a Closed Circuit Rebreather (CCR) works.

All CCR units have two main jobs. They recycle the breathing gas by effectively removing Co2 (Carbon Dioxide) out of the Breathing Loop, and replace the metabolized oxygen needed to sustain life.

The Co2 absorbent is one of the key ingredients that allow Rebreathers to work. Without Co2 absorbent (Sofnolime, Sodasorb, Extend Air) the Co2 that is produced as a waste product would be recirculated and re-consumed, creating toxic levels of CO2. The proper rotation of absorbent as well as staying inside manufacturer limits for absorbent duration is paramount to survival.

There are 3 different types of Closed Circuit Rebreathers on the market in regards to how the oxygen is injected and controlled in the Rebreather.

Electronically controlled CCR’s have electronics built into the unit that measure the oxygen content in the breathing loop via oxygen sensors and will inject oxygen via a solenoid valve into the loop based on setpoint values programed into the controller.

Manually controlled CCR’s have some electronics located in the Po2 readout located either in the handset or within the HUD(Heads Up Display). The replenishment of O2 however is done with the aid of a constant mass flow injector controlled mechanically by the operator with a manual injection block in order to maintain the Po2 at the operator programed setpoint.

The third type of rebreather is a hybrid. This hybrid type of rebreather can be used in either manual or electronic mode. The rEvo CCR that is used as the primary training rebreather at HSU’s Technical Diving Program is a Hybrid CCR. With the rEvo the operator has options. You as the operator are able to choose between Manual Operation or Electronic Operation

Our recommendation to divers seeking rebreather training is to select an instructor having several hundred hours of rebreather dives. Other important aspects of choosing an instructor are what type of training the instructor has received and what type of support the instructor can offer after certification.

I have over 20 years of professional diving experience. I currently work with both commercial and recreational applications of diving. The equipment I choose is based on the mission of the dive. I have been trained by some of the best instructors in the industry. Paul Raymaekers (owner and designer of rEvo) and Jason Fisch (Ocean Edge Outfitters) have been my primary mentors during my rebreather training. I am fully endorsed by the manufacturer of rEvo CCR’s and the North American Distributor for rEvo CCR’s. I am personally certified on multiple units but fly and instruct exclusively on the rEVo CCR.

More importantly you are not alone after certification. We have a strong and growing community of CCR divers who are always willing to log some bottom time. If you are interested in finding out more about this amazing diving technology please contact:

Kevin Marks

Director of Training

Hawaii SCUBA University/Island Divers Hawaii

808-620-8402 kevin@islanddivershawaii.com