I purchased an APD Inspiration Rebreather in 2001. It has its good points and its bad points so I discuss some here. Actually it's very difficult to comment fairly at times. There are bits I'm not happy with but conversely AP/APD are just the people to deal with. Their attitude to customer service makes them my preferred supplier regardless of the idiosyncrasies of the unit. I would not want to be using dive kit like this without people on the other end of the phone who want to help. I will run over some of the features of the item as I bought it and as I see it now as a novice rebreather diver. Take it as just that. I may well change my ideas in some areas later but I am not a novice engineer. When you start rebreather diving you are warned that you are beginning again and that is really how it is. You have much to unlearn and even after many dives and now with a growing familiarity with the unit I still keep discovering things where what I used to do is now wrong and skills that I once learned slowly that are now useless, even embarrassing. <sigh>

This is the computer handset. There are two of them. They're a bit simplistic but when operating them in gloves in the cold they are reasonably chunky and you get what you ask for. The trick is that the first one to come online is the master and runs things. They both monitor and display the three oxygen sensors and if the master quits the slave takes over at once. The switch at the bottom is power on off and the three buttons are sliders that move about half a centimetre and, I believe, sweep magnets over sensors to reach inside the sealed case. These seem to be a running fault as everybody seems to have their own tricks to get a sluggish switch to work. Actually the seals aren't fighting much. The computers are hosed back to the scrubber unit so they always stay at ambient water pressure but in air. Don't think "Computer? Like my dive computer that reads my depth and time and plans deco for me?" These are simple voltmeters to read the oxygen sensors and present it as a partial pressure reading with a control loop to drive the solenoid to add extra oxygen when it is below a preset level. They certainly were not designed by instrument makers but I suppose I'm not a scuba equipment manufacturer so I shouldn't complain too loudly. They perform well maintaining the loop ppO2 quite accurately even when I was going through the beginner phase of relearning buoyancy control.

This is the wing inflator and fallback reg so you can breath the diluent tank if it all goes pear shaped. Currently I think it sucks. Every unit I have dived (all 3) needs treating nicely or it free flows - even my brand new one - and it has too many buttons . However other people with far more experience of the unit than I have seem to tolerate them so maybe I'm being too picky. I added the whistle because one has saved my bacon in the past but it has to be the Buddy part as the connector is a weirdo, like nothing like anything else I have seen. Amusingly the manual on the thing warns you not to use it to deflate the wing but to use one of the two other dump valves. <sigh>

This is the mouth piece. If you hold the black bits and turn the white bit so the mouthpiece points down you close off the opening. This is needed so you can take the thing out of your mouth without allowing water to run back into it. This would at worst flood the loop so you can no longer breath from it and make you several kilograms extra negatively buoyant or at minimum sentence you to a dive with gurgully sound effects. The stories I hear from when people have failed to do this seem to indicate that the design of the unit successfully keeps water from the important bits. I changed the jaw-breaking mouthpiece supplied for a comfortable Scubapro one.

At the bottom of both counterlungs are the injectors. The left hand counterlung (right hand image) is equipped to inject the diluent, air to newbies like me, and the other one injects oxygen. They both have a gauge so you can monitor the contents of the tanks. You need the injectors for the manual control of the unit. You add diluent on the descent to make up for the loss of gas volume as the pressure increases and the oxygen injector enables you to drive the system yourself if the inject solenoid quits. You can see that my unit has a plate to fit an alternate injector. This allows you to carry two diluent mixes. Admittedly people who dive sophisticated mixes don't seem to have one but if I like it I have it. Since taking these pictures I have rearranged the gauges to run down the inside edges of the counterlungs. This makes them more intuitive to get my hands on them. There is an incredible amount of Velcro and stitched channelling on the counterlungs, most of it is unused and much of it incomprehensible.

These are the T pieces on the shoulders of the counterlungs. They have blades inside to try to ensure that any liquid entering the loop is dumped into the right hand (exhale) counterlung. It's harmless there and you can drain it out after the dive. You use this mix of exhaled body fluids and other gunk to gross out the more squeamish team members. This is the main dismantling point for the hoses so you can give it a good clean out with disinfectant. Since what you breath out is going round and round this is considered a life expectancy issue as it could culture up some very interesting stuff.

Yeah I put my name on it. I don't like wearing brand names (except Honda who I owe) so the id is me. I had lots of these stickers to reletter the race bikes after the inevitable happened. I don't actually need it for identification as if you're diving with a couple of rebreather divers I'm the one with the yellow wings. (I hate that black on black look.) Overall I'm not very impressed with the harness. It has too many clips, adjustments and fiddly bits. There are 6 clips to do up all with their own pull to tighten adjustments. What I need the D rings that are trapped between the wing and my shoulder blades for currently eludes me and why does the wing have a hole in it so you can fit a suicide bottle? Nostalgia? At least the collar for the bottle gives me somewhere to stow the reg on the 100% side. I added this as the manual gives bailout examples which call for breathing 100% shallow but I fitted an Apex sliding shut off valve, as recommended in the manual, to stop anybody making a big mistake deep.

This is a before and after picture of the bolts that hold the new style clips that snap the back cover on. In picture one you will see the nuts and shaft that project into the body of the rebreather and scrape the paint off my tanks. In the second picture you will see what happens if you remove the screws and put them in the other way round. No gouge now? Well sorry no. My tanks are already gouged. But what the heck? These are only life support items made of steel that I will immerse regularly in sea-water. No. I'm not impressed. This is typical of the standard of the secondary engineering on the unit - it lets down the excellence of the primary design.

These are the integrated weight pockets that I bought as an extra. I finally figured how they fit, it only took a couple of months, they might work a bit better now. The trick it to tie-wrap them to the matching bands under the back plate. If you don't do that the moment you try to pick the unit up they drag forwards, pulling over the vertical strap they locate around and getting horribly knotted up. The other thing you can do is run an awl through the Velcro and tie-wrap the bottom shut. I don't do dumpable weights as I consider that, as yet, I'm too young to die. I need 12Kgs in a dry suit in fresh water and 15Kgs in the sea. This pretty much matches my 12L single rig which is rather sad. It renders the total Inspiration very heavy. I was hoping to shed some weight going from twin 300bar 10L tanks but it certainly doesn't feel like I have.

So, over all what do I think of the thing? Well, despite the gripes I like it. I am prepared to believe that rebreathers are the future of diving but this isn't quite that rebreather yet. What would I like to change aside from the general poor quality of the execution of the design?

◊	Harness improvements. It must be possible to make it simpler. You need to wash it so you take off all the hoses and clean them down in the sink and then it's time for the counterlungs. These were fitted with a sewing machine so it's time to fit screw on covers to the first stages and put the entire thing in the bath. This is silly.
◊	Better computer displays. These things are far too clunky and could do a better range of warnings. People have died because they didn't switch them on, which you must admit isn't APD's fault, but auto switch on when immersed is hardly complex electronics. Forgetting to switch up a set-point is also a serious problem and needs only a depth sensor (even just a pressure switch) to beep at you until you do something about it.
◊	The hose connectors catch you out as a novice as you can start to unscrew the wrong part and it is very hard to retighten them if you slacken it. On a unit this expensive any special tools required to fix basic problems should be in the box. It's only a bit of tube with some studs in it.
◊	The AutoAir is a joke but it is so designed in that you are effectively stuck with it. I will very seriously look into fixing this with something that does not need babying and that is suitable to hand off. As it stands the Inspiration is effectively designed for solo diving. Its breath-the-wing feature worries me. It will let you breath in from the wing automatically if the tank runs out and then you exhale into the water. If you ever get to that point it means you have just discarded a lung full of buoyancy. I would far rather it went hard in my mouth and gave me the choice.
◊	I was a little disappointed with the weight. With my additions it tips the scales at 30kgms but I suppose that is to be expected. This is including two 4Kg tanks, about 3Kgs of Sofnolime and a couple of kgs of gas. Then there are two first stages, gauges, computers, hosing and such. I expected it to be less but it's built to survive and I can't complain at that. Like all AP stuff it won't break with a bit of real world use.

What have I done to it? Well the first fix is to look in the book and see how it refers to breathing the oxygen on bail out. But how you ask. By fitting a regulator on the oxygen. The manual describes this and warns you to fit a slide valve to reduce the chance of anybody breathing this at depth with the obvious danger of an oxygen hit. I use a TX40 because I've always found them simple reliable regs and added the slide valve and a mouthpiece cover to make the point. It plumbs into the oxygen manifold and slips into the suicide bottle holder and is out of the way and easy to reach underwater although impossible to replace.

The Bob-o-matic Auto Diluent Valve. This is a wonderful thing. You don't need it but it's handy. On an Inspiration you need to make additions to the counterlungs on the descent and then fine tune your buoyancy by adding/loosing a little counterlung volume. Now the purists will argue that this is not minimum volume but it works for most of us but when I have my hands full of camera I hit a snag. The old open circuit way of trimming your buoyancy by holding just the right amount of breath doesn't work any more. I can trim for down by exhaling through my nose but trim for up involves touching the diluent add button and I don't have a free hand. The ADV is a conventional regulator that adds diluent to the loop if the pressure drops below ambient. On the descent it feeds more gas as the counterlungs compress as the pressure rises so I can still breath in and when I am sighting the camera breathing in enough to just empty the lungs gives me that little puff of gas I need to trim upwards. Magic. Bob Howell sells the body and you add parts from an Aqualung DV and some other parts and it works beautifully. See Bob's Rebreather site for more details.