Wannabe a Rebreather Diver?

I have been a scuba instructor since 1975 and in that time I have encouraged everyone capable of breathing to become a scuba diver.

June 12, 2023
Wannabe a Rebreather Diver?
Wannabe a Rebreather Diver?
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Now I find I have to be more careful who I fill with hope – not everyone should be a rebreather diver. So why have I changed my tune? Why not sell everyone a closed circuit rebreather (CCR)?
The sort of people who shouldn’t buy a CCR are those who:

  • Believe a pre-dive check is something you only do on courses;
  • Knows everything after one dive course five to ten years ago;
  • Only fix gear if it breaks;
  • Use all their air because they paid for it;
  • Don’t need a computer because they only dive for a feed – yeah right.

Recognise the type? If that is you, stop reading and go look at pictures of crayfish.

Most CCRs are quite robust but they house electronics in some form or another and these don’t mix well with seawater. Choose your CCR carefully, look for simplicity of design and operation. The simpler it is, the more likely you are to make the right choice if things go wrong – anything man-made will eventually break!

Printed on the top of my KISS Classic mCCR were the words “This device is capable of killing you without warning”. That was a bit sobering as I had just unpacked it. I have heard and read that CCR advice in many forms since then. With thousands of dives to my credit, I am aware of the power of the sea and I have also lost friends in diving accidents. If you are looking at getting into CCR diving, here is some advice for you.

Firstly, stay within the manufacturer’s recommendations. For example, why buy a CCR if you cheat on CO2 absorber duration? Sorb is cheap and CO2 detection is the one capability missing from mainstream CCRs. If you read the statistics, there are plenty of examples of divers who ignored manufacturer’s advice, and tragically drowned.

Next, choose the best instructor you can. Look for one with personal integrity who has extensive experience with your type of CCR – that experience and attitude is worth paying for. The training agency is not as important as they all set similar standards. In the end, it is the instructor running your training that will give you peace of mind – or not. Will they stay in touch after your course? That is when you need them the most.

The overriding advice to all qualified CCR divers is to follow a checklist. That means we have a process for activating the CCR and ensuring it is safe to dive. When preparing a CCR, allow about an hour to do it properly, it won’t take that long but you may have interruptions. A checklist will allow you to complete the preparation safely without missing any detail.

You must abort the dive if there is a fault with the CCR – or fix the fault. Don’t believe that it is okay to dive with one failed oxygen sensor. If one fails the other two may also. That little stream of bubbles may look harmless but you only have a small cylinder of oxygen. Treat an amber battery warning light the same as a red warning. Get the idea?

Choose a CCR buddy who is going to be part of your redundancy. The buddy must not only be able to self-rescue if they have a problem, they must be able to help you. A thoroughly briefed and practiced buddy will be an asset.

If there aren’t any local CCR divers to dive with, then look for a conscientious tech diver. They are more likely to understand your passion and concerns. CCR-friendly dive centres invest in the industry and will be delighted to support your CCR needs. That is where you can expect sound advice and guidance based on experience, long after your course.

Trouble-free hours spent diving your CCR doesn’t necessarily mean you are a competent CCR diver. Don’t trust your CCR (or any dive gear for that matter); remember it does not have your best interests at heart. Practise your emergency skills so you develop muscle memory. An emergency is not the time to find out your skills are rusty. You can’t breathe water.

Try and keep an open mind. CCR technology is developing so quickly that it is a struggle to keep current. Today’s innovations, like the Shearwater NERD computer, will quickly become the norm for CCR divers. This is a classic case of technology improving diver safety. Read case studies. You should learn from others’ experiences, don’t make their mistakes. Changing a small bad habit may pay long term dividends.

If you are keen to discover another way of diving, a CCR may be it. Are you open to new ideas and: disciplined enough to abort a dive; maintain your equipment; obey the rules and are you prepared to get the best instructor you can afford? If the answer to any of those questions is no, go back to Scuba. You have no business buying a CCR!

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Tony Howell

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