From May 18 through the 20th, I had the pleasure of attending Rebreather Forum 3 in Orlando Florida. Rebreather Forum 2 was held 16 years ago and much has changed in the rebreather diving industry since that time.
To help you better understand my perspective on this event, I am a PADI Master Instructor with no technical diving knowledge and have used two different rebreathers in a pool while attending a PADI Tec Xplor day. Compared to most people in attendance, I was at the extreme low end of rebreather experience. Based on the feedback we’ve received from our readers however, it’s safe to say my experience is comparable to much of the diving population.
Are Rebreathers Safe?
Every time we’ve mentioned rebreathers either via Aquaviews or on our Facebook Page, the typical response is that they are a death trap. With this preconceived notion in mind, my mission was to find the honest answers.
Unfortunately at this point, it’s not a simple answer.
Rebreather Units Are Safe, but More Complex
The actual rebreather units themselves are constantly becoming safer and more reliable. As use continues to grow, so does research and development, making each new unit a significant improvement on the previous models. According to most studies shared, rebreather accidents were almost always attributable to diver error, not equipment issues.
Unfortunately, rebreathers do require a more extensive pre-dive safety check. The use of checklists and dive buddies or supervisors who double-check the checklists were constantly stressed at Rebreather Forum.
If you compare what you should be doing before every open circuit dive, the differences aren’t too vast. You should check your gear before setting it up. You should check your tank o-ring before attaching your regulator. You should test breathe off both second stages while watching your pressure gauge to make sure everything is working properly. You should analyze your air for contaminants and oxygen percentage. You should review everything with your buddy.
Now how many of you actually do what you’re supposed to do?
Divers Aren’t Safe
If you miss a step on open circuit, it’s not typically the end of the world and can be relatively easily fixed. On a closed circuit system, cutting a corner on your check list can be fatal.
At this point, all training systems are unit specific. So in theory, if you have the proper training and you follow your checklist, rebreathers are incredibly safe. If you only dive a rebreather once a year or every few years or choose not to follow your checklist, this is when rebreathers become potentially more dangerous than traditional SCUBA.
Many presenters at Rebreather Forum gave comparisons between rebreather related fatalities and pretty much anything you could think of. More children are killed by power windows in the US each year than people die on rebreathers, yet power windows aren’t feared. More people die bowling, driving their cars and falling down stairs than die using rebreathers.
While this is completely true, the statistician side of me can’t ignore the sample population. As a percentage of people using rebreathers, the accident rate is uncomfortably high. However, several presenters pointed out that up to this point, rebreathers have been used for very extreme diving. Deep depths, cave or wreck exploration, using cumbersome video or photo equipment or getting close to big animals are the main venues rebreathers have been used in to this point.
Also, as I’ve personally seen training dive professionals, divers tend to have delusions of grandeur at a certain point. Instructors teach their students to have a buddy help put gear on, do safety checks and dive together. Then the same instructor throws their gear on over their head, checks their gear alone and heads into the water without a buddy to set a dive float or down-line.
This type of activity has also happened in the rebreather world.
As with open circuit diving, technical rebreathers and technical rebreather training is designed with decompression, overhead environments, more exotic mixed gases and self-reliance in mind. If you have a problem while using a technical rebreather in a technical environment, you figure out the problem and fix it at depth.
Also similar to open circuit diving, recreational rebreathers and recreational rebreather training is designed to be done without decompression with direct access to the surface using more common gas blends with safety, not self-reliance, in mind. If you have a problem on a recreational rebreather in a recreational environment, you flip a switch on your regulator and head to the surface on open circuit.
Recreational rebreathers are also designed to force the pre-dive safety checklist. They guide you through prompts, they check aspects of your unit independently and they don’t function until you’ve taken the necessary safety precautions. Some people will argue that computers can’t be trusted or what happens if the battery dies, but in a recreational setting if something goes wrong, they’re designed to be as failsafe as possible. Just like regulators are designed to free-flow instead of restricting air supply, recreational rebreathers are designed to get you back to the surface in an emergency. The people who fear rebreathers due to not trusting the electronic side of the equation are more than welcome to borrow my wheel to continue planning their dives, but I don’t personally fear electronics underwater.
Benefits of Rebreathers
From higher-ups at PADI to cave explorers to underwater videographers to fish researchers, the benefits of rebreathers were very similar:
- Longer Bottom Time. We heard examples of 300 foot dives with a 20 minute bottom time and total dive times of over 3 hours. And this isn’t difficult on a rebreather.
- A Warmer Dive. Since air is recirculated, it has additional humidity which keeps divers warmer on a dive.
- Improved Interactions. Sea creatures hear our bubbles and generally avoid them. With a rebreather, you can get much closer to the action.
- Easier For Technical Dives. Instead of clipping off 10+ tanks, a rebreather diver can reach the same depths with a fraction of the tanks. Additional tanks are still required for bail-out, but bottom gas is greatly decreased.
Just as the evolution from horse collars to CO2-inflate BCD’s to our modern BCD’s have improved the diving experience, just like going from tables to the wheel to modern computers improve the diving experience, rebreathers make many aspects of diving better. But just like modern BCD’s and computers, they aren’t necessary for every dive experience.
Rebreathers Are a Tool
Just like dive computers, rebreathers are simply a tool. If the types of dives you would like to make would benefit from the use of a rebreather, go for it. If the types of dives you plan to make would not benefit, stick with open circuit.
Why Are Rebreathers So Expensive?
Second only to “why are rebreathers so dangerous?”, the most common question we receive is in regards to the high price tag of units. Based on what I heard at Rebreather Forum, this is another not-so-easy answer.
If we’re looking at technical rebreathers, we’re looking at a combination of research and development costs, international safety certification expenses and simple supply and demand. The US doesn’t currently have a standardized safety certification process for rebreathers, but Europe does and testing is neither inexpensive or convenient. Testing must also be re-done if there are any changes to any component of the unit as well as periodic re-certification. With a relatively (compared to recreational open circuit divers) small population of users, these costs are spread amongst a fairly small group of users.
Looking at recreational rebreathers, the price justification is virtually identical. Much of the research and development expense has been covered by their big sibling technical units, but the automatic systems and more user friendly interfaces require additional R&D expenses. Not only do these units have to meet the same safety certifications, but they need to meet higher standards set forth by training agencies like PADI to qualify as eligible units for recreational training. At this point, the number of units designed for recreational use that are actually available for purchase is very small, skewing the supply and demand model.
As more manufacturers develop recreational units, over time prices should decrease.
Should I Get a Rebreather?
Only if you plan on getting trained to use it
As I mentioned previously, rebreathers are a tool. If you live in an apartment with a great manager, you probably have no need for a circular saw (unless you like working with wood). If you plan on diving 4 or 5 times a year on vacation in the tropics, a rebreather is probably not the best investment at this point in time. If you’re going to the Galapagos and want to get closer to hammerheads, if you want to explore caves and cenotes, if you want to work on your potential professional photographer career, it is worth looking into.
Should I Attend the Next Rebreather Forum?
If you are a dive professional or are very interested in rebreathers and their main applications, I would strongly recommend considering it. Since the last one was 16 years ago, I’m not sure what the plan is for the next Rebreather Forum. The last one was held during the relative infancy of rebreather usage outside the military, this Rebreather Forum was at the beginning of the potential recreational rebreather boom. The next one may be in a year or it may be at a more pivotal point in rebreather diving history.
If you resist using a dive computer and think rebreathers are a death trap, I’d suggest saving your time and money for a nice open circuit SCUBA vacation.