FREQUENTLY ASKED QUESTIONS #4

WHAT TO ASK ABOUT ANY CCR

Not all rebreathers are the same. Ask the right questions, narrow down your options and make an informed decision that suits your needs.

Is your Closed Circuit Rebreather CE approved?

It should be because CE approval means rigorous third-party testing for important performance issues such as work of breathing. Don’t let people tell you CE approval doesn’t matter. It is a crucial, independently ascertained set of standards made with reference to human physiology – common to divers worldwide – not just to Europe.

If the unit uses oxygen controllers (has an automatic option) does it have independent dual controllers?

It really should do - otherwise you have no backup in a system you are relying on to keep you alive! Only AP Inspiration Rebreathers offer dual independent oxygen controllers.

Is there a backup power source?

If your unit uses battery power to function, then there should be an independent backup battery pack and a mechanism to switch seamlessly (and automatically) from one to the other should it be required. AP Diving has this sort of redundancy built in to the Inspiration range as standard.

What is your CCR’s depth rating?

If Trimix / Heliox is used instead of air as the diluent supply and modification is made to the bailout contingency, AP CCRs can be dived to depths of 100m+. They are routinely tested in unmanned trials to much greater depths and dives to depths of 110-120m have been achieved many times. Expeditions to 130m+ are now common.

Does your CCR you’re looking at have Over-the-Shoulder (Front) AND Rear Mounted Counterlung options?

There really isn’t a great deal of difference between the two, but there are advantages to each. Only AP Diving offers divers the choice with both options carrying CE Certification.

What type of oxygen injection system is used in your CCR?

Different systems on the market include: Constant Flow Orifice, diver adjustable Variable Flow Orifice, a Static Solenoid or a Dynamic Solenoid. If you are looking for a CCR with the option of automatic set-point control, look for one with a Dynamic Solenoid for continuous and instant reaction to changes in oxygen partial pressure in the diving loop. All AP Inspiration rebreathers offer a Dynamic Solenoid as standard and as a result set the benchmark in O₂control accuracy.

How well will your CCR maintain constant PO₂ during ascent? This really comes back to controllers. During ascent the partial pressure of oxygen in the diver’s breathing loop can drop dramatically and to hypoxic levels as the ambient pressure drops. Unless the CCR’s oxygen controller has the ability to react correctly and rapidly to these changes, the diver is at serious risk and the unit is poorly designed. AP Inspiration controllers reactively control the variable solenoid valve timing ensuring oxygen pressure is maintained with benchmark accuracy, +/- 0.05 bar of setpoint. Even during fast ascents, there is no need for manual intervention.

Does it have a CO₂ scrubber performance monitor?

The scrubber bed is where carbon dioxide is removed from exhaled breath. The factors affecting scrubber duration – depth, work rate and water temperature – are too varied to offer accurate predictions of scrubber life for all possible conditions. Since the chemical reaction that takes place in the absorbent generates heat, a smart way to monitor performance is to compare temperatures across the bed and display that to the diver. The manufacturer’s stated duration guides (3 hours or 2 hours) are conservative as they are achieved under deliberately harsh test conditions. The AP Inspiration Scrubber Monitor takes into account the actual conditions and displays in real-time what is actually going on. It takes the guess-work out, allowing you to extend scrubber duration with complete confidence.

Does it have a CO₂ Sensor?

By following a few basic ‘rules’ and sticking to certain guidelines, CO₂ breakthrough can be avoided, but many divers feel more comfortable and secure with this type of sensor in place. The AP Diving CO₂ Sensor is an ‘active warning device’ designed to alert the diver when the CO₂ content of the breathing loop is approaching a dangerous level. This could be due to depletion of the CO₂ absorbent canister or incorrect assembly resulting in CO₂ bypass of the canister.

Does it have Heads Up Display (HUD) and what information does it show to the diver? A HUD is a useful tool, but some are at best overly complicated, at worst confusing – the last thing you want at depth, or in critical situations. A HUD should only convey exactly the information necessary for you to fly your unit safely, including warnings when PO₂ is outside set parameters, when battery power drops, and when your scrubber is reaching the end of its effective life. The AP’s unique fibre-optic (no flood) HUD keeps it simple. Green for Go… Any red, check the handset.

Can your CCR be upgraded for Technical Trimix Diving?

Not all CCR divers are interested in technical diving, but if you one day decide to go down this route, ask yourself… will I have to sell my unit and start again with a new rebreather? If you choose an AP Inspiration Rebreather you won’t have to - because all 3 Inspiration models can be configured and upgraded to suit all levels Rec to Tec.

Does it have a real-time Nitrox / Trimix computer designed and manufactured by the same people who built the CCR?

It should. Some CCRs use controllers and computers from third-party suppliers. This may suit some risk models and manufacturing philosophies, but not ours. The more you mix and match, the more likely you could face compatibility issues, glitches, or worse – not something you want to be worrying about as you fly under a wreck at 80m! AP Diving’s Vision controller and integrated deco computer is the product of over 15 years research and has been tried and tested in labs, in-water and in depth. Our Vision systems are bespoke and purpose built for the kit they run, so you can be sure they’ll deliver the performance and reliability you expect.

Does your CCR offer a PC Interface and Dive log download?

A nice feature to have. Amazing when you can send that log to the manufacturer for diagnostics. AP technicians routinely use the dive log memory for diagnostics when servicing units or offering advice to customers.

Does it have visual and audible alarms for crucial issues such as low or high PO₂, high CO₂, and scrubber life?

Many CCRs only have visual alarms. At AP Diving, we believe it is vitally important to have both. Think about it. In a critical situation, under stress, your judgement may be impaired, you could be distracted. With both senses alerted you are much more likely to recognize the warning and respond in time.

Are parts and service available worldwide?

If you travel, it would be nice to know that in the event of something breaking, a replacement part is not sitting in a warehouse someplace on the other side of the world and a day or two away from access to shipping. AP Diving make 95% of all products in-house which means spares can usually be shipped the same day. A simple call or email to the factory here in the UK and you tap into our legendary customer service. Most of our staff are divers themselves and we will always endeavor to go the extra mile to keep you diving.  Add to this our global distribution network in which AP regional distributors and many dive centres worldwide hold stock of common spares and you can be reassured - we’ve got your back.

How much service is required?

Leading-edge industrial design using solidly made quality parts all put together in an ISO 9001 factory – or shoddy components outsourced to the cheapest off-shore knock-off house? One approach leads to less servicing and longer life. No prizes for guessing which. At AP Diving, we manufacture 95% of all components on-site in our UK factory. We test 100% of our components on-site at our UK Test Centre. And when things do go wrong, we have an after sales and servicing department run by knowledgeable people who love diving and love helping you dive.

AP Inspiration rebreathers meet and beat all the above criteria, because at AP Diving we’ve been asking questions like these since we began CCR manufacture over 25 years ago.