You’ve heard the opinions from both sides: Proponents happily state that “rebreathers are the wave of the future!” while naysayers argue that “rebreathers are death boxes!” Which side is correct? In a way, both. It’s true that a rebreather can malfunction and rebreather accidents can be fatal, but it’s also correct that rebreathers are better than ever, and there are ways to safely circumvent issues that can lead to a fatal accident. Among all the opinions, anecdotes, and conjecture surrounding rebreather use, what are the true hazards and benefits of rebreather diving? Let’s take a closer look.
Understanding How a Rebreather Works
Rebreather functions vary from one type and model to the next, but all perform the same basic task: Scrubbing air you have exhaled, removing metabolic carbon dioxide and allowing you to breathe it again while maintaining a safe oxygen level. In the event of an electrical or mechanical malfunction, a serious diving accident could occur, and could potentially lead to death. Standard practice is to carry an open-circuit bailout.
Hazards of Rebreather Diving
Since 1960, approximately 200 rebreather deaths have occurred, with the majority of them having happened during the last two decades. Some of the most hotly debated fatalities have involved highly experienced divers, many who had been on very deep dives, explored remote wrecks, and traveled deep into complex cave systems using scuba gear. The questions surrounding these fatalities are numerous.
Preparing a rebreather for diving is more time-consuming than prepping scuba gear, and cleaning a rebreather following a dive is also more time consuming. It takes discipline to care for a rebreather properly, and some people simply are not ready for the responsibility. If you are someone who feels it is a hassle to rinse your scuba gear or dive even if your equipment is overdue for service, you are probably going to find maintaining a rebreather difficult. And, while you might be able to get away with diving on gear that hasn’t been perfectly maintained, you will not be able to do so with a rebreather. Complacency plays a major role in diving accidents, including some involving rebreathers.
If you tend to push your limits, rebreather diving may not be for you. It takes time to build the muscle memory and skill required to dive in advanced environments. While your rebreather might allow you to go deeper and stay underwater longer, it’s important to build skill gradually. Successful rebreather divers extend themselves gradually to assure safety.
Benefits of Rebreather Diving
There are two main benefits of rebreather diving: Extended dive time and the ability to observe and photograph marine animals without disturbing them.
With a rebreather, you can greatly extend dive time, all while carrying about 40 cubic feet of breathing gas. Decompression requirements are less stringent as well.
Without the bubbles and noise that accompany scuba gear, you’ll see more fish, and you will encounter rare species more frequently, in many cases. Whales, wahoo, tuna, and dolphins are often frightened of bubble noise and will avoid divers; those using rebreathers encounter these and other shy species more frequently than scuba divers do. If you enjoy underwater photography, you’ll find that your subjects are much more cooperative when you are not emitting bubbles.
Only you know for sure if a rebreather is right for you. The units are expensive, training is extensive, and you need to be willing to pay close attention to detail and spend time on maintenance. If you find the benefits of rebreather diving appealing, consider moving forward. If not, stick to scuba. Either way, you will continue to enjoy exploring the marvels the underwater world has to offer.