Evolution Rebreather

Evolution Rebreather

The Evolution CCR has finally arrived...

After many months of waiting... it’s here.

And boy was it worth the wait.

The Evolution is the new sibling to the Inspiration rebreather made by Ambient Pressure Diving. Possibly the best known closed circuit rebreather on the market.

The Evolution uses the same principles as the Inspiration, electronically maintaining  of the PPO2 in the loop at the theoretical ideal “setpoint”, measured by three separate O2 cells and controlled by redundant controller circuits... but it’s been designed with all the learning from the 7 years of production of the Inspiration

The other point is... it’s significantly smaller and lighter than it’s older brother... ideal for those who travel or are simply of a smaller build


The side view shows you the same over the shoulder counterlung design which gives you the most natural breathing resistance.

Also clear are the new style cover catches which are made from a rubber like material which is unlikely to get broken and is easy to release with cold hands (Just the thing for Stoney Cove in winter!)

The lungs and wings come in two colour choices, Yellow as on mine or grey...

What you can’t see is a redesigned harness with integrated weight pouches, but you can see some of the repositioned D-rings which make it much easier to clip of stage cylinders. (As I say, they have learnt from experience)

The hoses, mouthpiece, gauges etc are almost identical to the Inspiration Classic (as has become known)

A departure from the Inspiration sees us with a single handset... the dual controllers are now located safely away within the scrubber head.

This handset not only gives the PP02 readings as per the old unit, but also a host of other information.

The electronics now incorporate a full Nitrox or Trimix decompression computer... with all deco information displayed on the handset

Also visible in the picture is the Heads Up Display or HUD, the two green lights show everything is OK and the PPO2 is held within band... flashing or RED requires attention and indicates many different states.

The hud is controlled separately from the handset and theoretically you could cut off the handset and still monitor the unit on the HUD



Open the catches and swing the unit open (rather than removing it) shows the interior.

The Evo is a smaller unit and carries a pair of 2L cylinders. One for Diluent to make up volume changes whilst descending and for buoyancy control, the other Oxygen for maintenance of the PPO2. (I’m not going into rebreather theory here... the are plenty of sites more qualified than mine)

All the internals are held in place by simple Velcro straps.

You can also just about make out the diluent manifold on the top left (behind the cylinder) which is used to feed gas to the Wing, manual injection and the ADV (If fitted)

It’s all pretty tightly packed, but there is still room for additional lead if you need it nearer the top of the unit.

The main criticism I have is the amount of lead need. The unit is lighter than the Inspiration but has approximately the same bouancy from the counterlungs... as such you need to add more weight to counteract this....


From the top of the head, you can see the fibre optics that feed the HUD and the warning buzzer... which most people keep within the case, rather than strapped to the hoses... personally I find it a little difficult to hear.

You can also see one of the three ”lift & twist” catches that hold the head inside the scrubber.

These replace the screw fixings on the Inspiration and seem effective...


Time will tell how robust these prove over the lift of the unit.

The head is sealed by a barrel or piston type O-ring. In many ways more resilient than the compression O-ring on the Inspiration... but it can be difficult to remove the head from the scrubber... and when I say difficult... I mean VERY difficult. It does get stuck... there has to be an easier way to do this.

With cold hands, it can prove impossible.

Here you can see the scrubber assembly opened ip.

The three cells... which are not the same as inspiration cells (see below), the battery compartment (modified from the Inspiration to counteract “battery bounce”) and the Oxygen solenoid.

You can also see the plugs and cables for the “Tempstik” which is used to monitor the temperature at different points in the scrubber core... giving an indication of the state of the scrubber and where in the stack the reaction is taking place. This is used to give a good indication as to the usable scrubber left... It’s not a CO2 meter however. Recognise its’ limitations and you wouldn’t be without it.



Here’s a closeup of the connector to the Oxygen cell. This is completely redesigned...

Being co-axial, it’s easier to connect and removes the strain. It’s a simple push fit.

Any problems due to moisture on these connectors can usually be solved by simply twisting the connector to ensure a good contact...


I’ve only had a few hours on the unit, but so far I’m really impressed.

Build quality is excellent, the innovative HUD and Handset is marvelous.

The ability to connect it to your computer (via the same connect as the Tempstik) and download all the dive information (And I do mean all of it... Depth, decompression, temperature, voltages etc) is useful. Also the ability to upload new software to the onboard computer will save having to send the unit back to base for upgrades.

I don’t like how much lead I have to wear and I’m concerned at how difficult it is to open the scrubber. Time will tell if this gets any easier.

I also find that the HUD gets in the line of sight of the wrist mounted display.. you can change the side of the hud from left to right... I however wear the wrist display on my chest... very similar to the Inspiration handsets.

All in all... I think its’ an excellent unit, well thought out and designed for the user... not for an engineer...

Try one, you’ll want one...

But there is currently a 10 month waiting list... 

Updated September  2007