Buying Your Rebreather

Open circuit diving is open to almost anyone. You can start a PADI course at age eight and continue to dive until you are 80. Other than a desire to participate and reasonable good health, there are just a few things that should preclude anyone from taking part.

For rebreathers however, this does not hold true. A greater degree of awareness and discipline is required. It is not that it is difficult to master, it just requires that one not be complacent. If one neglects responsibility to the machine, it can be fatal.

Example: a diver had been using his fully closed-circuit rebreather for only a short while. He had become comfortable diving his unit and it now seemed simple and reliable to use. On one particular dive, he decided he was experienced enough to teach others while using the unit himself. He did not recognize the extra task of loading that is required and became side-tracked by his students while preparing to enter the water. Mistakenly he never turned his unit on. Hypoxia occurred and he died.

The vast majority of accidents on rebreathers are caused by something as simple as not turning on the oxygen or the handsets. However, it is the subtext one should be aware of rather than the final cause. By this I mean it was more a failure of the diver getting ahead of himself—having loading tasks that were too distracting that caused this particular accident.

When you purchase a rebreather, be prepared to dive it for an extended period of time before doing the type of dives you are accustomed to. Rebreather skills must be over-learned. You must be aware that the diver is the weak link in every fatal situation.

This article is not intended to explain how different rebreathers work. If you are considering buying a rebreather, you should educate yourself on the different rebreather types and how each of them work. For a full explanation on rebreather modes use the information guide below.

Rebreathers have been around for a long time, much longer than OC. The idea was first conceived in the 17th century with the first working system in 1878. In the first and second World Wars, a number of different rigs were used, with units taking on their present design in the 1960s.

Now, commercial interests have further fueled their evolution. This has minimized the failure points and made them viable propositions for the technical/recreational market. At this point, 10,000 technical and recreational divers are deciding that rebreathers are the tool of choice.

This article will not tell you what unit to buy but rather what to look for and what to avoid when deciding on a purchase. So why should you listen to my opinion?

I have over 1500+ hours of rebreather time. My first dives were with the LAR V O2 Rebreather in 1987 with the military. Since then, I have purchased the following five rebreathers: Cis Lunar, Inspiration, Atlantis, Megalodon, Kiss and a Hammerhead. I have dived at least eight other rebreathers that include: Mk15.5, Prism, Dolphin, BMD, TP2000, CCR500 and others. I am an IANTD Rebreather Instructor Trainer “T” for most of these units.

Although my rebreather purchasing experience has not always been positive, my entire rebreather diving experience has been completely worth the headaches. Nothing could make me give up my closed-circuit equipment and dive OC again! Following are a few purchase experiences from my past that you too might relate to one day…

I waited 18 months (on a three-month promise) after I paid a deposit on the Cis Lunar before delivery. On receipt, it didn’t work and I waited another six months before it worked properly. I received the Inspiration pretty much on time. I waited 12 months on a six-week promise for a Megalodon.

I dove and supported rebreather trips around the world in areas as diverse as the Arctic and Amazon. I have used rebreathers for cave and wreck diving, up to depths of 450 feet and I have had more electronic failures than I care to remember.

From these experiences, I have compiled a set of questions and criteria, in no particular order (except for rule #1 which should always be at the top of any rebreather list) to aid in the purchasing of your rebreather.

RULE #1: TRAINING, INSTRUCTORS AND DIVING ATTITUDE.

There have been a number of fatalities on rebreathers. In most incidences it always came down to diver error. The time to start good habits is from the get-go and with a good instructor. Skilled instructors, providing comprehensive training, are important in all facets of diving, but even more so in rebreather diving. If you pay $5 for training you get $5 worth of training. Consider renting rebreathers for your courses. This way, you will find out what rebreathers are all about before making the big investment. Once you have completed training, build experience slowly and never become complacent with your rebreather or your emergency skills.

RULE #2: LEARN ABOUT THE DIFFERENT MODES AND MODELS OF REBREATHERS.

What type versus what model of rebreather is hotly debated. Here is a quick summary of the modes. At the bottom of this article there is a list of websites, videos and books that you can use to further educate yourself on rebreather specific models.

There are 4 basic types of rebreather.
1. The fully closed rebreather, such as the Inspiration/Evolution, Cis Lunar, Megalodon, Prism, Optima Orebro’s CCR1000 and the MK15 series (no bubbles electronically controlled)
2. The kiss such as the Kiss rebreather and the COPIS Meg rebreather (metering/manual addition of oxygen no bubbles)
3. The semi-closed passive rebreather such as Halcyon, Halcyon 80, Odyssey, K3 and BMD (occasional venting of bubbles, gas addition keyed to respiratory need)
4. The semi-closed active rebreather such as the Dolphin/Atlantis, Azimuth, Drager Ray (constant mass flow adds nitrox continuously, bubbles every five breaths or so)

I believe there are many well-designed rebreathers. None of the models readily available on the market are inherently dangerous. All have points that could be improved and some will suit certain types of diving better than others. Many people find it hard to accept that the unit they paid 1,000s of dollars for has shortcomings. Regardless of the expense and the unit you purchase, I guarantee that there will be parts you would like added, improved and/or removed.