The most common question asked is “What unit should I buy?”

There is no simple answer to this question. There are many good rebreathers, each with its own pros and cons. Purchasing a unit is contingent on the answers to the following questions:

  1. Ask yourself, what do you ultimately want to do?
  2. How much of an investment can you make?

Andrew Driver wrote the following article seven years ago. A few updates have been made to the article to help facilitate the purchase of your rebreather equipment.

By Andrew Driver, January 2001rebreather-dpv
Rebreathers are a contentious subject! There are certain groups and individuals who believe rebreathers are inherently dangerous. Others, including myself, believe they are safer for deep dives than Open Circuit (OC) and far more fun, logistically easier and are the future of diving as we know it. In my opinion, OC is dead for technical diving and rebreathers will be the SCUBA of choice for nearly all technical and many recreational divers. It may be another 10 or 15 years before general acceptance, but it will happen. If you are one of the growing number people considering a rebreather purchase then read on because rebreathers have arrived!

The many advantages to using a rebreather are listed below:

  • Gas efficiency
  • Deco efficiency
  • Helium cost efficiency
  • Warmth
  • Hydration
  • Silence

These advantages all add up to a better way to dive!

Rebreathers are certainly not a panacea for all diving ills. Listed below are some of the realities one has to accept to be a success:

  • Discipline and good training is imperative
  • Expense
  • Time for mastery
  • Complexity

These listed items are not unique to rebreather diving, they also apply to OC technical diving. Please realize that the “human factor” should be considered the weak link. As units and diver methodologies evolve, deaths in rebreather dives will certainly occur. These unfortunate deaths—in all instances—result because of inadequate training, attitude, experience and inability of the individuals diving the unit rather than the unit itself. I would like to stress that all rebreather problems can be recognized and remedied by the practiced, educated and aware rebreather diver.

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 vesus 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.

  • Rule #3: What will you use the unit for?

    Buy a unit suited for the type of diving you are doing now and what you intend to do in the future. The Dolphin SCC rebreather is a starting point for many people because of the price point (around $2500-$3300). However, this is not a good investment if you ultimately intend to dive beyond 130ft/40M and want to dive for more than a couple of hours and enjoy the benefits of a fully closed system. Speak with people who have experience with the different types of rebreathers you are looking into and talk to those who are doing the type of diving you intend to do.

  • Rule #4: Get as much information as you can.

    Some information you hear will be good and some poor…so be aware. Individuals who own or teach a particular brand of rebreather will naturally have a bias toward that unit. Take these considerations into account when you absorb that information. Interview your potential mentors and ask them about their experience with regard toward rebreathers. Keep in mind that OC teaching experience is not relevant to rebreathers. SCC experience is not really relevant to CC (closed-circuit) experience either. Another huge benefit and part of the learning curve is to contact other rebreather divers in your local vicinity. Find out which units are common in that particular area.

  • Rule #5: What is the makeup of the company selling the unit.

    A number of rebreather manufacturers have come and gone in the last 10 years. Some taking deposits with them into bankruptcy. Cis Lunar has gone out of business yet made a comeback. Biomarine went out of business, as did the manufacturers of the Odyssey (US), BMD (Canadian), UT240 (US), K3 (US) and Fieno (Japan). You can’t buy a new MK 15 series unless you pay Carlton $50K.

    In some instances, there are cottage industries that service these units and do a good job of it. When you purchase a unit, you should consider whether the unit is being made by two people in a garage or if there is a company with assets and history behind it. Just because a unit is made in a home shop doesn’t mean it’s bad though! It just means they are far more susceptible to problems in production, maintenance and vagaries of the economy.

    Ambient Pressure Diving, an entity of AP Valves (really its AP Valves with changed names for legal purposes) is the manufacturer of the Inspiration and is far and away the largest manufacturer of FCC rebreathers with shipped units numbering around 5,000 worldwide. AP Valves has been around for 30 years and it’s a fair bet they will be around for a while yet. Consider whether the manufacturer will be around in the next 4-5 years. If so, what business does it have to keep it going?

  • Rule #6: Will your unit have a second hand value?

    You may decide you want to sell your rebreather, to trade up or to take up golf. Either way, it would be nice to know you could sell it at some future date. Many units have a decent second-hand value. A second-hand purchase is a good option, but buyers must beware. Be conscious of the person selling the unit as there have been a number of scams on eBay. Don’t pay the money until you get the unit.

  • Rule #7: How many units have been sold.

    Find out how many units have been sold and the history of those units in service. Reliability of electronics, reliability of parts, work of breathing, comfort, surface attitude, its buoyancy characteristics and manufacturing failure points are all considerations. The best test for how these things stand up is for the units to be out there and dived by ‘Joe Public’ or ‘Joe Military.’ If a unit has been dived by a large number of people, you will get a better idea of its performance. Unless you are part of a design team for a rebreather, it is not a good idea to be a beta tester for a rebreather company. If you are diving one of the first 20 units produced by a company, then in all likelihood you are a guinea pig. From experience, it can be incredibly frustrating to wait months for a unit, only for it to fail.

  • Rule #8: Time your purchase.

    A general rule of thumb…Anything you buy in the rebreather world takes 3-5 times longer to arrive than the manufacturer promised delivery dates (actually, it is much better now than in 2007). Even with the most reputable of companies, you may have to wait for months if you buy during the wrong season. Many people buy in spring just prior to the diving season. There are two drawbacks in this thinking.

    • First, everyone is doing the same, so you may end up having to wait.
    • Second, you are opening yourself to the temptation of diving beyond your limit.

    As a bare minimum (for the qualified OC Trimix diver) it is recommended that one does 25-30 hours on one unit with air at depths less than 30m/100ft. The next 25-30 hours with HE to depths less than 180ft/55M. If you buy the unit in the off season, you are giving yourself the time to build experience before the temptation of deeper diving appears.

  • Rule #9: Cost

    Don’t buy the most expensive rebreather then seek the cheapest training. The best investment you can make on a rebreather will be the money you spend on training. If you can’t afford it, don’t buy it. Think about what you are getting for your money. Does it have deco electronics? Do you have to buy a back plate and harness, BC, etc.?

  • Rule #10: running costs & maintenance.

    Operational expenses are not much more than standard OC with most rebreathers, but there is always a chance you might get stuck with a big bill if you drop it or break it. For individuals doing a lot of HE diving it can be considerably cheaper. You will also need to factor in the cost of Sofnolime/absorbent, maintenance, batteries and training. Skimping on maintenance costs is not recommended. For a FCC course, expect to pay around $1,500 for training and do a minimum five-day course with at least 500 minutes of dive time.

ALWAYS REMEMBER!

The real issue with rebreathers is not necessarily the unit! The main issue is the training you receive and the attitude knowledge and ability of the diver using the unit. In essence you must rely on yourself. If you can’t do that don’t buy a rebreather.

With Moondog Outfitters, you will receive the expert training you need to enjoy and succeed with a rebreather!