Closed Circuit rebreather training, Sales, Travel

Silent Explorers

This review of rebreathers is for divers who are thinking of training, and are looking for some advice from a seasoned professional.   This is direct from the gut, and it  is not supposed to be pretty but honest.  There is no brass for me to shine, no profit to be made, and if feelings are hurt it is just the way it is.  I speak from experience having owned all of these units to get a fair appraisal and if I speak of a bullet that i have dodged then I make it plain.

The review is in chronological order starting with SCR's and then into 15 or so different CCR's.  There are some funny anecdotes that also contain a few that are admittedly a bit offensive in nature, so I have posted a link to these later.

To read about my history and experience, please visit my regular website at

Things to consider first is New or Used. 

I have a lot of experience here as I have taught many courses over the years with divers choosing both new and used.


New is new and you don't have to wonder during your precious week of time off for the CCR Mod 1 course that your unit is going to have bugs?  Nothing beats a fresh CCR from the factory!

The price of ANY CCR on the market today is well worth the price to get a tool that can entirely change the way that you dive.  A CCR is an investment in technical diving and I can say within reason that they all work, but quality of build or quality of electronics can make a big difference in price.  If you shop for a CCR, it is well within your rights to look all over the country you reside in, as well as look at foreign destinations.  I have lived through periods of time when I could import a rebreather direct from manufacture in UK, and have divers price shop me to discover that they could fly to the UK and buy the unit with training lower than I could?

Distributors can be greedy bastards and you will know if a new rebreather is an honest value if the manufacture allows the CCR instructor / Dive Center to sell the units direct.  If you have to purchase the CCR directly from a "distributor" and not from the instructor, then you should walk away!  Your instructor / Dive Center works far too hard in a very competitive industry to be cheated out of a commission.  Now listen to the lecture as this is important for your future.  If you want an instructor to give you a quality course, take care of your life, and consider that they will also be there in future for advanced CCR training, then don't cheat them.   Your instructor owes you nothing if you give them nothing.  Commissions on all CCR's is very small, but it is important for a full time CCR Instructor / Dive Center to receive a commission no matter how small.  Your choice to pay attention as I don't lecture twice to people who don't listen.  Lecture over.   

Used is used and you have to accept that there are going to be bugs.  There are ALWAYS bugs with used units!  But I will not be a hypocrite and say never to buy used, as I have frequently sold my used units or my students used units.   There is a big difference between buying a used unit from your instructor, and just buying a used unit on the web.  Your instructor is going to be stuck dealing with "issues" and I can tell you that no instructor has extra time in their Mod 1 training to stop and fix bugs.  Bugs will always slow down a class and they can be so serious that you have to physically cancel training until the fix is mended.  
Wiring is the biggest bug in rebreathers that can ruin a class, and worse.  Wiring is key to reading your Po2 display, to sending Mv signals to computer, to running solenoid, etc.   I have had countless students who have purchased used units that have black wires on the sensors.  Black wiring means that the metal has corroded from salt water diving and often breaks.  Because most divers dive in oceans, more so than only fresh water lakes, then it is most likely that a used unit may suffer salt intrusion.  It is not a leak per say, but simply that salt in the air, salt spray, or a few drips of salt water splash onto critical wires.  And since all rebreathers react poorly when sensors are wet, then it is often necessary for divers to open a CCR in a salt water environment.  Green corrosion on Molex connectors, or other style connectors is bad!  But I have also seen divers who have used "Super Glue" to hold wires onto connectors?  I just taught a CCR course with a diver who purchased a very nice used unit and it had "black wires" and it took hours to carefully replace new Molex connectors.

Always start training with fresh new sensors so you know from the beginning how to monitor a fresh sensor, how to change on 6 month rotation, and not bet your life on "used" life support.

Battery wiring, battery compartments, rechargeable batteries.  Consider the location of the batteries that power the solenoid, or Po2 display.  Some CCR manufactures put the batteries in stupid locations, or that require tools.  Always assume that you will have a dead battery after just changing batteries as things get left on... Ease of replacement, and quality of battery compartment can be critical.  For rechargeable batteries, you have NO idea how they will react in a real dive, especially repetitive dives.

Counter Lungs - holes are often caused by negligence or in case of style of BMCL on one ccr that is very problematic to holes if laid forward?  I've had students who have used units that previous owner was too aggressive and pulled a bulkhead apart on gas lines that permeate the lung.  Other divers I have seen pull out a blacken gross tampon of an absorbent pad that the prior owner forgot to clean or remove?  Counter lungs that have been cleaned with harsh chemicals can stress plastics and you never know what a prior owner used?  I've owned neoprene OTS counter lungs that always had pin holes, always!  Ironically it was not a problem as they only released a tiny bit of gas on expansion.  Consider if you can "User Change" your own counter lungs, or do they require factory service?  Be aware of complex bellows type counter lungs, sheesh!

Loop, DSV, BOV -  Depending on age, loop hoses do need to be replaced.  A pin hole in a loop hose sounds horrible, but it can happen and it can be sometimes repaired with an AquaSeal type adhesive.  A patch may get you through, but you need good loop hoses.  Look for sagging on hose ends, check marks in rubber that signal the hoses are on way out.  Elongated hoses can occur from divers stretching hoses.   DSV need regular service with o-rings and lubrication, as well as regular change of DSV flapper valves.  Again too aggressive of chemicals for sanitation have been found to damage or shrink critical flapper valves.    BOV do fail contrary to divers opinions, they can and do leak.  Some BOV are too complex and that should be a signal.  If you have a simple BOV, then it should be easy to clean, service.

Regulator service and IP pressures.  This depends on if your unit is an eCCR (electronic solenoid), hCCR (hybrid solenoid with oxygen orifice), or mCCR (manual with oxygen orifice only).   Divers monkey with things they may not truly understand and when it comes to the correct IP (intermediate pressure) then it can be critical to have correct pressure.  Simple things like OPV (over pressure valves) can be removed when they are important safety features.  Check for any green or white residue inside of DIN filter, or remove a low pressure port plug and look inside.  Signs of corrosion are a bad thing for regulators as it can lead to failure, or send crud down the lines to internal components.  

Don't be afraid of a used CCR as there are currently too many brands of rebreathers competing in too small of a market, as well as it is common for divers to jump from model to model of different CCR's.  The market is flooded with used CCR's and there are always good values.  Just remember for every good value out there, that there is a lemon and I have had to disrupt entire CCR courses to address safety issues (bugs) on a students rebreather. 

Subaru Graveyard  

This is a TV commercial for an automobile that an owner drives for ever until they drive it off to a graveyard for well loved vehicles.  Well that's advertising for you, but you need to understand that there is NO Subaru graveyard for CCR's.  It is my experience that once a diver gets bitten by the CCR bug, that they will often buy a CCR to dive it for a couple years and then change units.  Of my students over twenty years of time that if a diver stays active in technical diving that they will at least own two different models of rebreather.  I have some students who have purchased four different rebreathers and none of them have been due to disappointment.  Rather the diver loves CCR's so much that when they see a new model, new feature they just buy and sell.  

I use this Subaru Graveyard analogy often during CCR demos as I have seen divers wait, wait, wait and ponder the right CCR to only have wasted years on dinosaur OC to finally pull the trigger on a CCR.    If you are looking for the "Perfect" CCR, well so have I and its been at least twenty years and I am still looking. Don't waste time missing some great dives when you could be diving a rebreather, any rebreather.


This is the most important factor you can make in diving a rebreather as your instructor is the example that you follow to safely dive a rebreather.  How many years have they been diving a CCR, and how many years have they been teaching?  Also how many levels of CCR training can they offer?  Experience is NOT easy to achieve in a competitive dive industry where a dive store owner / instructor may need to juggle between open circuit teaching and rebreathers.  Do you want an instructor who is teaching Peak Buoyancy classes in the morning and then rebreather in the afternoon?   Not to say that this can't happen, but if you have a dedicated CCR instructor who only dives a rebreather then you know the Muscle Memory is fresh.  What is the instructors history of teaching, do they have years of open water, followed by technical diver training?  The more experienced your instructor has can only help,  as an instructor builds upon experiences they have had in basics to advanced training,  that helps them handle the stressful situations that CCR can offer.  

Your instructor should have an active following of CCR divers that stay with the instructor for important mentoring and continued education.  All CCR courses are taught with a basic Air Diluent Mod 1 level regardless of your prior experience. It is quite likely that you will want to progress from this first mod to extended depth levels.  In today's sorry environment of rebreather manufactures restricting instructors from training "other" units, and dive training agencies caving into so called "safety" committees that the rules are changing daily and its not good.    It is a difficult thing for a new diver to try to figure out if their instructor is "Hog Tied" by restrictions of a manufacture or if they are free to follow a responsible dive training agency standards.  What this means is that your choice of a rebreather can greatly impact your future of training.  Consider if you buy an XYZ brand CCR and your instructor can train you to Mod 1, ask them if they can offer training to more advanced levels.  If you by chance buy a rebreather model that you like, but there is NO instructor in your region that can do additional training, then you are forced to travel.

Look carefully at a "Flashy" name rebreather center, and look more closely at the curriculum and the staff.  It is human nature to want the best in as short of time possible, but with a CCR there is NO value to rushing a course.  Most every CCR Mod 1 course is an intense five to six days of twelve hour days, with six to eight required dives.  This is not a place to shortcut!

Cheep Hotels Dot Com 

I tell it straight,  and I tell you when I screw up, as I have.   I shop online just like everyone else, and I look for bargains when I need a hotel during travel.  A clean bed, a hot shower and quite place is all I need.  Now this is not to say that I have not walked into a hotel lobby, as a prostitute was walking out after a drug deal and I thought "what stinks like shite?"  only to discover after I checked in and went back out to my truck for luggage that the prostitute had shite herself on the entryway carpet.  Yes that really happened and I stepped in it!  Now this is gross analogy, but it should stick in your mind and not on your shoes as it did in my case.  

I have seen divers make this El Cheapo mistake too often when they look for a rebreather,  and the most common case is when they want to buy a "Side Mount" rebreather that really only has a specific purpose of Side Mount and not general diving.  A cheap rebreather is a cheap rebreather and you must compare apples with apples to understand if you are buying a good used rebreather cheaply because the diver just got divorced, or are you buying a stripped down single purpose rebreather that is a stripped down single purpose rebreather. 

There are some great rebreathers that are basic kits that you need to finish, such as a BCD, a harness, Sensors, a Dive Computer / Po2 display, etc.... Rebreathers new or used that come in stripped fashion only sound economical until you need to build them up.  Don't always assume that your OC wing or harness is the best fit for a CCR.  With a CCR the wing should be minimum and in the 28-40 lb lift capacity only as you don NOT want some giant Zodiac inflatable boat as a wing.  A harness may or may not be ideal for a rebreather if it was used for doubles.  Some gear may work, but you need to take your instructors advice. 

There are other rebreathers that are ideal for warmer climate cave diving in side mount configurations.  This does not mean that it is the best choice for deep shipwrecks in Great Lakes.  A diver that is going to only use the rebreather for side mount cave diving, then go for it.  If you are a shipwreck diver that is buying a low price rebreather and trying to make it fit, then you are making a bad decision based on price.

SCR Review Summary - Note I deleted history review here - see main website

*There is NO value to diving an SCR today market, and the above listed SCR's are out of date.  The new idea to introduce an eSCR into the dive industry is a monumental waste of divers money and time.  The marketing gimmick is to have "Training Wheels Rebreather" and then the diver will later upgrade to a CCR.  

*There is no value in trying to revive an out of date semi closed circuit rebreather( s) like Dolphin, Ray, Azimuth, Submatix as it is cost prohibitive if parts are even available.  These items are fine for a collector who wants a piece of history only.

*Do not attempt to modify an SCR into a CCR as there are better and safer alternatives in new or used CCR marketplace.

*SCR's are just as time consuming to build, and pre dive test and are NOT any safer than a CCR.  Do not waste time messing around with all the work for no return, as an SCR is limited.  You can dive any number of Recreational Closed Circuit Rebreathers and have simplicity and no greater time or risk. 

This next review is based on my 40+ years in the dive industry, my nose and instinct to smell a dog pile when i smell it.  I have extensive experience seeing this product being developed, seeing it being tested in Cayman's, its failures and too many divers who have complained that it never works!  I have not owned this unit as I choose to dodge the bullet and not take a head shot. 

​*Do NOT waste time with an eSCR!

Rebreather Review by History CCR's

AP Diving Inspiration/Evolution/Vison ( 8 out of 10 )

For almost a decade I enjoyed training divers primarily in the Midwest on Inspiration, Evolution, Vision CCR's until the manufacture AP Diving (Martin Parker)  made what I call a fateful decision that cost him the market in NA (North America) today.  At the time Martin was facing increased litigation outside of his home country of U.K. and the NA market was growing swiftly under a network of un-connected independent Inspo instructors.  It was literally a nightmare for him to manage ever single small order of units, dealing with wire transfers and import brokers, etc.  So he chose a couple guys to represent AP - NA, a Brit expat who had a lot of experience on the Inspo and an East Coast dive guy who had done a lot with the Drager SCR's.   Both of these guys I would call pathological liars as I have spoken to them face to face and had them tell me bald face lies about how they were going to market the AP units, how they were going to manage training and sales, etc... The hired an incompetent sales manager from West coast who was successful in selling the lies.  With their minions of service personal and inner circle, they brutally took away every sales and market that every individual instructor had built.  Boo-hoo, you say,  and yes it is tears.... but today after one of the partners had died of cancer and one is in prison, the sales manager is off selling Poseidon rebreathers?  Well the NA market for AP rebreathers is in the toilet?  That is not a small statement, but a fact that the first mass produced and very successful rebreathers and today still a viable unit is in the toilet for sales across NA?  This is astounding if you consider not only my representation of AP products from Midwest to attending Zero Gravity, then later Dive Tech, Cocos, Truk Lagoon....etc. etc. etc. and the king of the hill was the Inspo!  Travel in those early years was to carry all your cylinders, sorb, and to rely on the location to have oxygen or helium if needed in conjunction with compressed air.   I was part of a network of divers who showed early CCR divers how to manage rebreather travel as well as shipping resources like a palate of CCR cylinders to Chuuk.   Having been fortunate to meet many of the people in the industry that started CCR companies, I can today say without hesitation that Martin remains one of the best.  I respect that he maintains his own proprietary electronics, where many have folded to the success of Shearwater, only to have a copy of a copy of a copy of every other rebreather on the market with yet again SW electronics?  And it was a sad twist of fate that two pathological liars who were chosen as the NA distributors would knock the AP rebreathers so far off the shelf that today what is still a great rebreather to be bottom of the list on units of choice?

AP Diving CCR Pros

Pros - I give Martin high praise for having one of the few successful CCR's on the market with his own proprietary electronics.   The unit is mass produced for efficient production cost and offers a lot of quality for the price.  Sadly the market in the U.S. was destroyed, so I can't speak for the NA market, but in Europe or at least UK the unit is still strong.   The unit works very well with good breathing characteristics, and AP offers a BMCL option.  Another option that AP has responded to is the Tech Frame so you don't have to dive the yellow/black plastic turtle shell.  The unit comes complete, but if you wish to exchange your own harness or wing, it is easy to exchange.   Martin was key to introducing the 3 liter Faber with Inline valves, and almost everywhere you can CCR travel , you will find these valves. 

AP Diving CCR  Cons

Cons - The hose fittings are a bit cheesy how the go together with split clamps, but they are durable and easy threads to work.  None of this left hand / right hand thread which makes me curse!  A simply thin or thick thread that you cannot misplace. 

Moisture on sensors was always a problem that caused cell errors and required divers to split the top of the electronics off of the scrubber can to "air out" the sensors between long dives.

The "Standard DSV" is too cheaply made with tiny set screws.  If parts prices were reasonable, then the standard DSV is not a bad choice as it works simply.  Another issue is there is NO large lever knob and you need to find after market for a lever?  While the AP standard DSV works, it requires two hands; with one hand to grip outer barrel and one to twist the inner barrel.

The AP BOV - OMG What a Mongolian CF!  I understand the value of "muscle memory" and this may be the downfall of the AP BOV as it requires two hands to "grip and twist" as does the original AP DSV.  I will not discuss the complication of servicing as it fails its primary task of being an "instant twist" to breath OC gas.  If a diver is in any jeapordy and may be physically compromised by low oxygen, high oxygen, or Co2 then they are not in any physical condition to use two hands to manipulate a BOV.  The concept of flip a switch has already been proven by several CCR on market, and by sticking with the muscle memory of twisting an inner barrel while holding the outer barrel was just plain not good?

At least when I was importing directly, the cost of replacement parts was not outrageous as it is today.  Considering that a "Distributor" would be buying in bulk to distribute to another market, then they should be buying lower than I was initially.  By the time you get two more hands into the pot, and then you put a small margin of markup then you have excessive prices.  Just compare the rate Brits pay in Euros to what Yanks pay for same bits....not right.  It was part of the Silent Diving NA distributor to take away any profits of the instructor/dive center teaching AP products and to make every profit for the distributor by selling direct to consumers.

​Summary: the AP line of rebreathers work very well and are a great value.  I have enjoyed diving and training divers on these rigs for at least ten years and have accomplished some amazing dives with AP CCR. 

KISS CCR's  ( 8 out of 10 )

It was a great pleasure to meet Gordon on the Nautilus Explorer CCR weeks and see his new inventions.  Being a very talented tool maker, designer and engineer, Gordon was able to have a concept drawn on a napkin and make it workable.   One of the first things to understand was that Gordon was NOT a technical diver, as he was an avid sport diver in BC and loved to tinker with ideas.  He built a rebreather that worked incredibly well until he took it in the water and it did not work?  So he went back and tweaked things until he made his KISS Classic and it was an instant hit.  When possible he used common parts such as MSR water drinking bags for counter lungs.  He wanted to have a BOV that with a simple twist went from CCR to OC and the concept was Keep It Simple (S ) and just bail out.  He didn't conceive of all the convoluted skills to try and make a failing CCR keep working, but if you had a problem, then Bail Out!  He didn't put pressure gauges on his cylinders as it was not rational to him since 15 cu. ft of oxygen would last you hours, why require a pressure guage?  Another oddity that I discussed with him on the Nautilus was that he first put the oxygen on the left side.  "Gordon, why do you have the oxygen on the left side, as all other CCR's have it on the right side?"   Well it really did not matter, and in fact some CCR's had oxygen in small spheres, or tiny cylinders mounted sideways... but most CCR's did have oxygen on the right side.  So Gordon conceded and moved the oxygen to the right side to conform.  I don't think Gordon was a conformist, but he did pacify the whiners.  And Gordon was ahead of many when he made the Sport KISS as he saw the sport market as the largest segment of the dive industry and he was actually terrified by the success and demand of the Sport as it was an open invitation to liabilities that he did not want to take on.  But Gordon had created a demand as his rebreathers were quite functional, reliable, and durable.  When sport divers started taking KISS rebreathers deeper, and deeper, the just kept on working!  On one of my tech trimix trips to Truk Lagoon we wanted to see some deep reefs outside of the lagoon and there were couple Sport KISS divers below 300 fsw having great dives when they were only "rated" to 130?   Now the KISS rebreathers needed a simple addition and the idea of the Titan MAV (Manual Add Valve) was conceived at a dive show in Tacoma when I was helping host a KISS CCR booth.  We had met with Tomar who was showing the Titan rebreather and we new instantly that the KISS would be a much greater CCR if it had a better way to add diluent to loop volume, and a way to add offboard Dil on technical dives.   The KISS Classic had a very reliable scrubber that called for 4-8 scrubber, but also worked well with 8-12 if you did not over pack the scrubber media. The fact that the scrubber tube was such a long axial bed, there was almost no chance that anyone would have a Co2 issue.  The only drawback was the water trap was at the bottom and was not drainable.  As with any CCR on any dive, you get moisture and having it trapped at bottom until you do a scrubber change means that you have accumulating water at the bottom.  The KISS classic has never won awards for ease of breathing, and it required that you be in a slightly upright position to breathe well.  And the basic electronics of individual little Po2 displays needed to be updated, and eventually they were modified to a Fischer cable to put on a Shearwater EXT computer Po2 display.  There was a sad bit of time when Delta P electronics were added, and a Delta P BOV that was the size of a Volkswagen Beatle!  Both have gone by way.  It was on a CCR photo shoot to Cocos Isle where I had invited Curt Bowen to train on Inspiration CCR, and on the same trip,  Bruce Partridge offered me the chance to dive his KISS Classic and he would dive my Megalodon.  It was a great trade as he had not dived a Megalodon yet, and I had not had a chance to dive the KISS.  Bruce then purchased a Meg and I purchased a KISS!  The photo of Bruce in Cocos also shows a small metal box in front where he was working on adding a Po2 controller to the KISS.  As most people know Bruce went on to build an excellent HUD for the KISS using the Smithers blinking code,  and of course he went on to make these computers called Shearwater that have had a modest success in the dive industry... Today I am still favoring the Sport KISS with its unique bi-axial scrubber, and small box container that remains my favorite KISS rebreather.

The KISS rebreathers passed on to a new owner and in same vein of a brilliant tool maker and engineer, Mike has grown the product line to several new models.  One of the first new KISS products that I tried was the GEM (Gas Extension Mechanism) and featured a simple canister, two OTS counterlungs, and a DSV with a passive breathing mechanism that expelled a percentage of the gas you exhaled.  It was driven by a side slung single cylinder, or the cansiter was attached to side of a back mounted cylinder.  I found it too difficult to breath, unless you were 60 feet or deeper.  It was not until the KISS Sidekick was produced that I really got excited.  Not for the original design as a sidemounted PSCR, but I saw the opportunity for a Bail Out Rebreather.  The Sidekick had an internal scrubber held inside the single lung.  To me the greatest failure in modern CCR's was that in event of a catastrophic failure, a diver would go back to dinosaur age of open circuit?  I tried several times to convert the Sidekick to a Bail Out Breather, but in real dives where there was stress or current, I found that you could not forget to baby sit the unit or it would flood rendering it useless in emergency.  Not to say that the Sidekick could not be utilized for a BOB, but it takes effort.   The next unit was the Spirit and it was again a new concept of a split axial scrubber, and unique wrap around counter lung.  It is second only to the KISS Sport as one of my favorite KISS rebreathers.

KISS has many great rebreathers available, and many-many used KISS units that are still a great value to divers of all levels.  They are in some respects crude in design, simple in ways of using common parts like MSR water bags for counter lungs, and they generally require a diver to use a tool kit to assemble and disassemble.  But they are durable and work.  

*I don't like the idea that I have seen recently where a kit was made to take a bad design of a DeltaP/Hollis eSCR and convert it to a KISS rebreather.  In today's volatile environment of nosy busy body "safety organizations" that are hiding an attorney,  and fascist group "manufactures safety" council that dictate impossible terms and tell training agencies how they can teach, that in this environment an instructor could take a broken concept of an eSCR and convert it with KISS parts to resurrect a hybrid rebreather that nobody could have liability coverage.  What do you call a bastard Hollis Explorer and a KISS rebreather, and who is going to be an instructor?  Would the instructor have to be an original Explorer Instructor as well as a KISS instructor, and considering that the manufactures council state that you are NOT allowed to teach more than one rebreather, what is this new Frankenbreather?  Stick with a proven rebreather, being one of the original rebreathers designed by KISS and leave the home builders to tinker with their own monsters.


First and foremost is the people who run the company have always been good people! After Gordon passed away, then Kim took over and now Mike is running the company with same good will to industry and how they treat people with respect.  I do not subscribe to the RESA bullshite (see Labor Day CCR news full explanation) but I do not think that Mike is Fascist bully, but rather he is probably a member by simply not understanding how much grief the group causes to individual instructors.

All of the KISS units of old and newest generation are still viable units as they are easy to upgrade electronics, or change components with modest expense. This makes the KISS unit very attractive to buy older or used units as they can be purchased reasonably priced and upgraded to suit the diver.

KISS makes many different configurations of CCR to suit a divers particular style of diving from back mount or more traditional CCR, to several styles of Sidemount CCR.  

The unit is very reliable, and fairly durable

A plus that can also be a minus is that the units are a kit that you are to assemble as well add your own harness, wings, electronics, sensors.  The minus is that when you purchase a unit, it is not the base price, but the total finished price that is real.


The KISS concept is for a manual unit which has its strength, but it does not have an electronic set point controller or brain to implement a test, pre dive set up,  or pre breath.  People who still argue about the dangers of a computer controlling their life support are plain and simple STUPID!  All you need to do is take their iPhone and throw it in the toilet as these people do not need computers in life.

The units vary considerably on work of breathing, with the Classic style KISS being a hard WOB in a diver level or slightly head down position, which is so in rage these days.  It usually requires the diver to be slightly up attitude to breath reasonably well.   For sidemount units, the WOB is very very dependent on position so a good experienced KISS instructor is important.

What the unit lacks in polished aesthetics, it makes up in workability.  The homebuilt look has been upgraded in recent years, but it still has a garage look.

I personally do not think that the current owner of KISS has the evil intentions that are implied by the RESA group, and I think it is ignorance of the working instructors in the field that Mike does not realize that he is hurting with the aggressive support that they offer to the little NAZI club at RESA.  There is NO reason that KISS should support the wrong that RESA implies as it only dirties any of the good that could come from a safety advocacy group? Ignorance is bliss.

KISS Summary -  I have enjoyed diving several of the KISS models and they have all worked.  The product is a durable and rugged design, with reliability at the core.   They are a great value at used or new

ISC Megalodon 7/8 out of 10

​​I purchased my first 2 Megalodon's ( a Standard Meg and a Mini Meg ) 2001 and they were delivered soon after the death of Will Smithers who programmed the electronics for ISC.   I felt fortunate to have two sets of "Smithers electronics" as this was the last set of ISC handsets that had both Po2 Set Point Controller as well as integrated Deco.  I was not able to get the helium unlock code as the widow did not want to deal with the liability.  Regardless, the Smithers electronics were the best on the market at the time and had incredible efficiency of battery life due to Wills programming.   I have dives almost, but not every version of the Apecs electronics, which were a huge disappointment after diving an integrated handset.  Not only did the Apecs not have deco, they did not have near the smart programming that Will put into the original electronics which gave it outstanding battery life.   But the Apecs electronics had more than just battery life as a deficiency, they had bugs.  It is ironic that it took ISC over 15 years to finally introduce Apecs IV electronics with integrated deco?  In addition to the electronics, ISC made a COPIS ( Constant Oxygen           ) as they were bending to the "computers are dangerous" crowd and the success of the manual rebreathers on the market.  My original choice for OTS counterlungs with ISC was the neoprene as my mentor Tom was diving them.  The neoprene counter lungs were very slim or low profile as compared with the boxy nylon lungs.  However the neoprene suffered pin hole leaks, and I knew this going in as I would dive with Uncle Tom on several trips and see his CL fizzing like an Alka Seltzer.   One of the contributing factors was the internal nuts on the soft neoprene that cut into the rubber and caused pin holes, as well as neoprene is prone to pin holes.  Still the neoprene CL were my favorite.   The electronics were ok, and were a lot more moisture resistant than other units on the market at the time.  Currently the new Mk 15 Meg has totally revamped head with opposite gas flow, as compared with original head.  The axial scrubber at 5.5 lbs was relatively easy to fill and fairly fool proof and if you dived it with color indicating sorb, then you could see the purple stain on the sorb.  The scrubber can is an aluminum tube which is very durable, and allows you to attach cylinders of many different sizes.  My personal favorite for tank brackets was the simplest design of the X-Bracket with either SS band clamps or nylon cam straps.   I do not like the current pin and hinge type "Shadow Mounts" .  My dislike is for ALL fussy PIA brackets that you add to a standard 3 liter cylinder.  My reasons are that I owned too many cylinders, and too many different rebreathers to be constantly taking bands, and brackets on/off to swap cylinders on different units.   It has been a frustrating company to work with as they unrealistically expect a CCR instructor to be loyal only to ISC, yet whenever there was a sale in a market where an instrctor was already established, ISC would send in their factory instructor?   With many aging electronics systems on the market, there are too many old units available for sale.  I do NOT recommend buying aged ISC electronics, only if you are buying a new Mk 15 head.  


The ISC is a durable platform with a solid can to mount a STA, and cylinder mounts.  They offer different height cans, and different sizes of radial scrubbers to accommodate long duration dives.  

The new Mk 15 electronics, head are a "Glass Half Full" scenario where they are a huge improvement over old electronics, but they have some downsides.  The new head has easy to install/remove sensor tray.  The HUD uses "Smithers" blinking Po2 code of 1/10's and is very simple to mind.  One big pro is that you can add a 2nd Shearwater hardwired handset, but only as a secondary.  Leon got into a pissing match with Bruce at Shearwater when every single ISC installed Shearwater computer flooded.  Bruce came out the winner as it was an install issue and obviously Shearwater went on to be 10x success of any ISC product.

The OTS counterlungs are very water tolerant, and they do offer a simple DSV as well as a BOV.     The unit in full size has very good mass ratio for buoyancy in water.   

The biggest plus in ISC inventory is my favorite the Pathfinder CCR with ideal size and best in water weight buoyancy.   

For aftermarket products, you can get Gonad Gear accessories; DSV, Lungs, T-pcs, BOV, etc....


The company is still difficult to work for as an instructor as there has never been any loyalty coming from the company and I am speaking of today with a key member of the dive community that has ISC shite on several times recently????   They do NOT support instructors with any ability to sell spare parts as ISC offers zero margin, and ISC takes direct sales away from instructors.

The product is not mass produced, so there is too much labor intense work to provide enough profit for the manufacture.  Since they are not a major military contract, they survive and struggle to compete in a saturated sport market with a very expensive product. 

The battery life of 9 volt batteries in head are only reasonable, but to change them requires screw driver as they are in sealed compartments.  The battery tabs on the 9 volt are weak.  The handset battery chargers, and the internal rechargeable batteries are CRAP (yes all caps) as they only last weeks or couple months at best?  

The hoses are durable, but stiff and limit head movement along with the T-pc on the OTS counterlungs.  You need to twist your torso to view rather than move your head/neck to see.  The loop hose O-rings are soft and you are constantly changing shredded O-rings. 

The Hose to Head and T-pc threads are right/left hand threads, and are a complete Pain In the Arse!  It is not only annoying to do "Rightsy Loosey, and Lefty Tightsy, but the threads are also very very fine and constantly getting cross threaded.  It only takes a bit of grit, sand or careless twist and you bung up threads.

ISC does NOT offer a reasonable BMCL, and the disastrous "Toilet Seat" of an attempt at BMCL was as described a disaster!  There are numerous units on the market that use IQ Sub BMCL, or Gonad Gear BMCL's, yet ISC is too stubborn to submit to obvious?

ISC Summary - Over all I have dived some of my deepest dives on the ISC Megs in both ocean and Great Lakes and it is a good product.  

Optima ( 2 out of 10 )

Phew, where to start with this abortion on roller skates?

See Anecdotes

Optima Pro?

Well I do accept that it does function as a CCR

After a decade, Lamar caved in and replaced the original electronics with Shearwater and he released a "packable scrubber"
Optima Cons

Mongolain Clusterphuck - Etymology:  A generally futile attempt to solve a problem by throwing more people at it rather than more expertise.

The original unit that I purchased fell apart, un-screwed by itself?  The use of "Good Ol' Boys" for the CCR Test Diver Team  gave Lamar a shallow pool as I don't feel the instructors testing the unit had enough CCR experience and were simply kiss arse Dive Rite fans?  I would hope after a decade that they unit holds together?  Fittings on counter lungs would un-screw, the DSV was too small and failed, the handset delaminated and never stopped failing until it was replaced with Shearwater.

The original design was Mongolian with a tall or long body that was not low profile.  The design required the cylinders to sit below the scrubber/head rather than aside.  The original design took every CCR on the market, and all of the work that instructors have done to support CCR travel with sorb, and cylinders and threw away any good and re-invented a "square wheel".   Seriously, the standard in the market at a time when CCR dive destinations around the world offered 3 liter steel cylinders with either Right Hand Diluent/ Left Hand Oxygen valves, or Inline Black Diluent / Green Oxygen.  But Dive Rite choose to use a stupid fat 27 cu. ft cylinder with Right Hand Oxygen / Left Hand Diluent, so they totally reversed the Oxygen and Diluent valve direction?  WTF were they thinking?  At this time, traveling with CCR cylinders were not approved as they are today with airlines, so it was key to have cylinders on site.  But to have the cylinders backwards???  

The original scrubber was an RPC (Reactive Plastic Cartridge) from Micropore, which is a cool concept but totally a pain in arse as they were expensive, listed as a very short duration, and very fragile to handle.  It was near impossible to get the cartridge at a CCR destination outside of Cayman?  It took a decade, but they now have an insert to do packable loose scrubber.  Finally!

The new hose configuration has shut off isolators that are Mongolian?  You do NOT need extra hoses routed to shut off oxygen to the solenoid as there is this valve attached to the cylinder that is simple to just shut off!  If you have to feather a valve which is required in training, why add extra hoses and extra shut off valves?

Optima Summary - Well I understand that there are divers who are diving this unit currently, I don't understand why when there are so many other units available?

Titan CCR  7 out of 10

​This is a great "little" giant of a rebrather that has had a very sad, sad history.  It was the brainchild of a diver who had some very clever ideas that worked very well.  It was one of the easiest rebreathers for divers to build and maintain.  It had back mounted counterlungs, inside a unique shell on the concept of a KISS Classic case but much easier to access.  Shearwater primary electronics, with a Shearwater HUD.    A rechargeable battery that was wet pluggable and mounted inside the shell.  And one of the greatest features was the Titan MAV (manual add valve) that was conveniently located at right chest level and was brilliant for adding onboard oxygen, diluent or off board gasses.    The scrubber was original designed for the RPC cartridges which I've already discussed as great concept, but fail on being fragile and near impossible to find at travel destinations and if so impossibly expensive.  Titan shortly then made a packable scrubber insert and the unit was a joy to dive. The problem lay in the manufacture that had a Titan sized problem with honesty and integrity.  If a diver had an issue with any of the electronics, sending a unit in to the factory was a nightmare that some never resolved, while others got 2nd hand units returned to them.  It was very unfortunate as the unit was a breeze to dive at any depths, easy to maintain, and Shearwater electronics.  The company imploded after it was sold to a company that did most of the manufacturing of parts, and this company found that the trail of carnage from customer service was unbearable and they gave the company back to the original owners. 

*see funny anecdotes page

Pros -

The MAV gas block is now used on several CCR's inlcuding: KISS, rEvo (copy) and Meg as I do.  It is intuitive, and located mid chest easy to access, easy to add off board gas.

​BMCL's were enclosed in (KISS Style)  frame that worked as backplate, very streamlined and stood upright very well

​Rechargeable battery in Shearwater handset as well as solenoid battery was wet plugable.

​Automatic Calibration mode, HUD, etc.

More and more unique features to list

Cons -

Original unit only came with RPC cartridge until granular adapter was made. 

The company was good at sales and marketing, however lacked integrity when it came to service and honesty?

*Summary - Sadly the Titan company went tits up and pooped on several good divers in the midwest.  This unit could easily be an 8 of 10 if the company kept its service and repair of issues.   I have dived this unit deep in ocean as well as deep deep Great Lakes shipwrekcs.  One of easiest CCR's to build, and comfortable to dive.

Poseidon MKVI  & Se7en CCR 8 or 9 of 10

Considering that there is NO 10 of 10 on the CCR scale as I am still looking after these many years, the Poseidon ranks up in the top of top!  I really did not fall in love with this unit, until I decided to retire from active teaching and took the time to understand the unit.  It was admittedly my mistake, and in retrospect I would go back and put more effort into the recreational CCR market and upgrade divers into technical CCR on Poseidon units as they gained experience.  When I upgraded my head to the new Se7en and yes that number kind of annoys me as it like a "Lisp" when you say THEVEN??  But damnation what a nice upgrade and any kinks in early software are worked out. Great job Sven & Ole in Sweden for getting your lingonberries lined up.   The unit is the most intelligent on the market, with the future already in sight for Solid State Sensors, as well as the computer program to do diagnostic Pre Dive Start Up.  It has great weight ratio, easy to build, comfortable in water, and easy to travel with.


The Poseidon CCR is ONLY unit with Intelligent Automatic CCR Pre Dive Tests with Go / No-Go

Has the best weight ratio for lightweight travel benefits, yet most durable construction.  This combination yields optimum in water buoyancy ratio to be slightly negative.

Equipped with EZ to switch from CCR to Bailout via BOV (Bail Out Valve)

Buddy Light & DIVA visual, audio, vibrating alarm built into HUD

EZ to build with simple hose connections, Pre-Pack or Packable Scrubber

Optional Over The Shoulder or Back Mount Counter Lungs

Recreational Options or Technical Options you choose from start and are easy to upgrade

NO proprietary or PIA fussy cylinder mounts, uses ANY simply cam band clamps, soft or hard

Training is SMART and focuses on basics of safety without garbage skills to confuse

The manufacture is NOT a Fascist bully trying to manipulate the market by restricting instructors or training agencies abilities to teach a safe CCR program.


​It is made in Sweden and while craft and build are highest quality, some of the Poseidon stock features like BCD or Harness are are too Freaking Liberal European!  Take that Sven,  and put it with your Ikea combination bed / dining room table??  Good news is that ANY other tech BCD Wing, Harness or Back Plate will easily fit.

​The factory scrubber is a "Pre Pack" Mo Pro cartridge, however I use the German made  pack scrubber as I find any unique pre pack cartridges too expensive or too hard to find when traveling.   We got to the moon with German engineers, and we now have an easy to pack retrofit Poseidon loose granular scrubber.  Can you say "Farfignugen?"

Some of the upgrade features include individual battery / computer brains that are pre set at 40, 50, 60, Deep operating mode.  To increase your diving depth, you purchase a new battery / brain.

​*Summary - without hesitation I can recommend the Poseidon Se7en as BEST starter or recreational CCR, as well as platform to upgrade into Tech CCR!  It is easy to train, easy to dive and easy to upgrade.

rEvo CCR 8 of 10

​Belgium succeeded from Neatherlands in 1830's and with the arrogance of French,  and stubbornness of Germans,  became independent.   The Dutch are quite likely happy to be rid of such dregs and live a peaceful prosperous life without the baggage that this group of people weigh down on the rest of Europe.  The language of this new territory is primarily Dutch, and they still wear wooden shoes today but the reason why is not known?

The rEvo rebreather is a Drager Dolphin/ Ray breathing loop with a unique scrubber that is split into two canisters, with a lid that allows gas to pass through.  The direction of the gas flow, the counterlung size and shape, as well as loop hoses and loop hose connectors were all originally Drager rebreather parts or design.  The original rEvo electronics were a total piece of shite on steroids, and these Po2 displays were called "Dreams" although the reality was that they were Nightmares to anyone who used them.  The original Dreams used a "Wack A Mole" tapping sequence and required a handbook and schematic flow chart to figure out how to turn on / off / calibrate.     The rEvo is constantly changed and an Instructor teaching a new rEvo unit is never sure what components have changed, but over the years the Shearwater electronics have slowly replaced the option of using 2 Nightmares, then 1 Nightmare and today possibly NO Nightmares and dual Shearwaters such as a Perdix Po2 controller and a NERD back up.    At this point if you are looking at a used or new rEvo, do NOT for any reason use the Nightmare option!

The rEvo is quite simply one of the easiest rebreathers to build and to dive, with generally excellent weight to buoyancy ratio in water.  The lung volume is adequate for almost every diver and being located in back make for a clean front.  I do NOT care for the rEvo harness, or wing and in every instance have removed the harness and replaced it with either a soft harness like Dive Rite Transpac or other.  


The top feature has to be the dual or split scrubber that always maintains 50% of the scrubber as fresh back up to primary dive plan, as well as it saves divers at minimum 25% of sorb that normally is dumped due to regular diving circumstances where you don' t have enough time remaining to complete another dive as you would not have any reserve.  Plus the dual scrubbers are mindlessly simple to fill and no need to worry about bad pack as you have two that only a total Fn'g idiot could screw up two fills?

The instructors are ALLOWED to sell units which is important that they are not cut out of the chain, however all parts are only sold by a distributor.    

The unit is very easy to build, with fewest primary o-rings that could fail.  It is simply reliable!

Low profile case includes the BMCL, and if worn properly has one of the easiest breathing back mount lungs.

The rEvo is one if not the easiest CCR to build with confidence that it will perform 100 % in the water.

It is the only CCR that I've owned where you can in 15 minutes (with glass of Scotch, n Cigar) totally remove the electronics and replace, retrofit or send only parts to service department.  It is also a user friendly unit to replace crappy electronics with aftermarket.

The rEvo is an 8 in position due to having solid Shearwater electronics, on it is own without SW the rEvo would only sit at a 5 or 6?


The arrogant company profile has to be its biggest Con.  On one hand I could say that I have not met a more brilliant rebreather engineer that knows more about sensors, or Co2 scrubbing than all other manufactures combined, however theoretical knowledge is good but he lacks any real actual experience beyond padding around with a Drager SCR?

The Fascist dictator style of bullying a made up safety organization named RESA is a cover up for couple of rebreather manufactures who only want to dictate standards that allow an instructor to teach on only their unit.  This is pure selfish bullshite and has zero to due with safety.   This greatly impacts a student in future if they choose to train on a rEvo and they are faced with limited instructor pool for continued education beyond Mod 1.

The case that encloses the rEvo is sharp and easily damages the wing, as well as divers need to be careful of how they handle the unit on benches or fabric boat cushions.  The case includes attachment fittings that are too precise and anal in attention to fit.  The tank brackets suck hairy monkey balls (the kind that get hairs stuck in your teeth) and upon purchase of my first unit, I had hacked the tank bracket and replaced it with a half or an X-bracket with cam strap.  Ironically now ten years later, the company has copied my hack with a cam strap attachment.  These tank brackets are expensive, and too fussy or delicate for me to have in my truck to bang around as they would get bent to hell??  The side brackets are equally fussy with poor placement of drysuit cylinder as it competes with diluent handle. 

The Harness is CRAP!  It deserves no explanation, except it is Shite and you need to replace it with a soft tech harness of the Dive Rite Transpac style.   Since the unit must sit high on your shoulders, there is an ache in your arch of back due to the weight distribution.  The original Crap harness has a sliding plate to put support on your bumm, but you cannot use this sliding plate with a good harness???

The rEvo Dream is actually a Farfigonym  (etymology: an engineered word using first term German engineering "Farfignugen" / onym or "root" of words that both spelled the same, but has a different meaning - simple example is Dream: 1. a series of thoughts, images, and sensations occurring in a person's mind during sleep  2. a terrifying or very unpleasant experience or prospect. And it is also a word that is spelled the same, but is pronounced differently 1. drēm     and  2  Nait, Mer )   Only a Belgium could bastardize any language to this extent???  If this sounds confusing, just get your hands on a rEvo Dream and you will soon discover is a total phucking Nightmare!  It is supposed to be a simple Po2 display that allows one or two sensors to be displayed.  And it should be simple, however with the original "Wack A Mole" type tapping sequence, and the nightmare of program schematics, it should be thrown straight into the deepest trench in the ocean.  I believe the "Me Two CCR"  movement, singled out those individuals who thought that the harder you hit them, the better they listen?   Nope, it was patience and cadence of your taps on the Nightmare???   The next version of the Nightmare is the P5 for Piezo switch and if owned an original "Wack A Mole" then it was temporary relief.  Only temporary as the P5 should be removed and thrown into a just slightly less deep trench in the ocean!

The Drager DSV exemplifies the reason that the Germans are not allowed to maintain a Bundeswher, as they have a stubborn tendency to repeat the same errors due to their arrogant superior precision on all aspects of life, including engineering.   German engineering is a good thing if you want to safely land on the moon, but then again we have had o-ring failures on space flights?  Stubborn precision yes, just don't give them an Army!!   The damned O-rings are precise and too tiny, and the tolerance of the DSV is impossible!  It is a PIA to service as it is intolerant of an average scuba instructor?  This thing could use a dose of Russian engineering by incorporating big solid O-rings that are over built.

*Overall summary  - The rEvo is a simple rebreather to build and to dive, with generally excellent weight to buoyancy ratio in water.  The lung volume is adequate for almost every diver and being located in back make for a clean front.  It is totally reliable at any depth and one of my favorite to dive, but not to teach due to the impossible arrogant Fascist leadership of RESA.   See anecdotes page

Prism 2 CCR   4 of 10

The re-birth of the Prism Topaz to the Prism 2 occurred when Bob Hollis who had already invested great sums into developing a CCR,  purchased the rights from Peter Ready.  It took Hollis 5 years to deliver a working Prism 2 and when they did, it had little to none of the remarkable features of the original Topaz.  The Prism 2 was a very-very cheaply made of Off-Shore Asian import plastics.  The only feature that made it viable was the Shearwater electronics.  Hollis was determined to take over the entire CCR industry with its wide dealership base throughout NA, Caribbean, Europe.  The idea was on a "Dr. Evil" world domination plan, and they held Prism 2 crossovers like mass Papal blessings.  I could not resist as I still like to try every new CCR, and I took the bait.  When I crossed over to P2 instructor, I realized that walking down any street in any town in America that if I were to swing a dead cat that I would hit at least 6 P2 instructors!  I saw the marketing of P2 rebreathers with FREE Training with purchase of a unit.... and that is the result of mass marketing in the dive industry.  Just what you need is to give away a week of hard work teaching a rebreather course to sell a rebreather???  The components are weak and flimsy with parts that have to be handled like an eggshell.  The P2 is just another run of the mill rebreather with little to no outstanding features.  When I dived the unit, it was annoying that to build the rebeather was like watching a fish out of water flopping on a dock.  You could not build it without it falling over,  lay it down and it tried to stand up?  Awkward clamps for cylinders, saggy harness, fragile scrubber, PIA clamps to hold scrubber to electronics pod, and components that would flake chrome off on first dives?  On the same Cozumel dive trip that I saw an original Topaz, there was a diver who had the lid on the head implode when he tried to dive it beyond 300 feet and the lithium batteries exploded in salt water?  Yes the bottom line is that a Prism 2 rebreather works today, but why bother as there are too many other units of greater durability.   It may be a good starter rebreather for a first time diver, but I don't think it would be a CCR to last.


Well it is cheaply made, mass produced, and mass marketed by a large conglomerate scuba equipment manufacture.

​It should work as it is simply a modified copy of every other rebreather on the market?

It has Shearwater electronics

The design of the regulator first stages is keen, but then any Hollis regulator will only last one year before a retrofit, or redesigned first stage parts kit?

It is comfortable once you are in the water, and it breathes well.


​Well it is Cheaply made, mass produced, and mass marketed.  The Dr. Evil world domination concept had a double edge to cut.  They decided to cross over every rebreather instructor worldwide and they did.  You could not swing a dead cat on any street in America, but you would hit at least three P2 instructors!  This drove the price down, and dive centers would give training away with purchase?

Weak construction is a reality when everything is bid out to lowest price vendor in Asia?  The benefit of mass producing a product for 1% of the market has only been done successfully by one UK manufacture,  AP Diving. 

The unit has floppy spine, as it does not have a real frame or spine to hold the unit stable while you build it.  If you stand it up, it falls down and if you lay it down if falls up??

The counterlungs are cheesy, and all fittings are weakly made.  The drains on the counterlungs are a left over and really are impractical?    The new design of BMCL look cheesy as all they needed to do is use or copy the IQ sub?  The hose routing for the counter lung MAV looks messy.

The scrubber is a "flour duster" and it is delicate in build so you must handle it like a carton of eggs.  I've never filled a messier scrubber with more dust than this unit??

The head with the battery compartment looks like an "Alien Cranium"  and is prone to leaking.

*Summary - Yes i do agree that it works.  I don't know why you need to bother when there are so many other better new units on the market.    There are also numerous used units that will last longer as they are more durably built.  Don't buy a cheap rebreather just because it is cheap!  See anecdotes page

Ron is stand in for film Matrix - shown here dodging a bullet

Ouroboros CCR Review

​Ouroborus - a circular symbol depicting a snake, or less commonly a dragon, swallowing its tail, as an emblem of wholeness or infinity.   A CCR designed by Delta P.   If only this unit could have swallowed itself in totality?  

Our'abortion - I dodged a bullet here and was one of the few times that I was mistakenly identified as  Kenau Reevs look alike.  Ok, granted I don't get that mistake often, but if you saw how I dodged a bullet then you would have said "yep that Ron dude is a stand in for Neo in the Matrix move!".   The only way a person could justify the ownership of an Our'abortion would be to swallow the "Blue Pill" and deny reality!  I understand the designers intent at making the newest CisLunar replacement, and the unit did have incredibly well crafted jig stainless steel tubing, fittings, etc.... however it leaked faster than a sieve.  The electronics were crap and all of them failed.  If you were to stand behind the statement that this is the only rebreather that meets the U.S. Navy standards for performance, then its time to move to Mexico!

* Dodging a bullet is an idiom that simply means that you have successfully avoided a negative thing. In this case I avoided an $18,000 dollar disaster due to divine providence.  Fortunately I have never owned an Ourabortion CCR, but I've trained plenty of cross over students who made that mistake.   

*Summary - no need to bash a disaster that is gone, but its good reading to see the
anecdotes page.  Phew!

JJ CCR    ( 3 out of 10 )

As I have told my students in past, there is always some benefit to experiences that you can use in the future, and if you don't learn from bad experiences you are not learning at all.  The JJ was a situation of wanting something that really wasn't there.  I was invited to be in a group of the first 6 JJ instructors in NA, so I drove to Utah to join Dave Thompson (gave Martin Parker the initial concept design for Inspiration) and divers from West to East coast.  The opportunity to be first to release a new CCR could be a big deal, at least it was in past experience.  The JJ was one of the biggest disappointments that I've experienced with new release of a CCR!

JJ Pro's

It,  just like 8 other CCR's that uses Shearwater electronics?

If you like stands, I guess this one is not that bad but personally I would go without bulky stands?

The swivel MAV is the only feature that is unique, and not bad.  The DSV, loop hoses, fittings are reasonable?

If you want to be in a "Cult" then yeah!!!

You can strap steel 95's to the side of unit for diluent and oxygen?

JJ Con's

Stupid Proprietary sensor connections, which means that you need to buy "jumper cables" from Narc 90 so in pinch you can plug in any "R22 D type"  as NO other idiot in the world would carry a JJ sensor as a spare.  So either choose to only dive with other JJ divers, or get real and buy jumper cables.  

Poor weight ratio of land mass to in water buoyancy due to the "air bubble" in the scrubber can.  You need to add extra weight that makes the unit a pig on land

The Can has a stupid scoop to slide the head into, which can only serve as a sand trap and also bites your fingers when you push the spring loaded button?

The BMCL are weak and prone to leak if you lay the unit forward

The battery compartment on the head is just plain PIA to access and stupid!

The unit is sold by a U.S. distributor that does NOT give an instructor any commission, expects the instructor to pay full retail for their teaching unit, and does not give any discounts on parts.  This is simply greedy!  Instructors work too hard to be shit on by distributors.

*Summary -  The JJ works as a CCR, but why bother is my opinion as there are too many other CCR's out there that are better, and cost less.  The JJ is nothing more than a slightly beefier Inspiration rebreather.   If you are going to make a bad decision and choose a JJ, then at least be smart and fly to Europe to purchase and do the training overseas.  This unit rates a "Lipstick On A Pig" rating

*Note below  I make a couple exceptions to the rule that I do not grade CCR's that I have not owned, but in this case my instincts were spot on for the first, and I speak from real world experience and not CCR forum "posting experience"

Hammerhead CCR 8 of 10

There are many things that I like about the HH or XCCR in the construction and smart design features.  And there is no real reason that I did not choose to training divers on this unit, aside from I just never got around to doing the cross over?   I give high marks to the quality of materials used, the engineering and ease of operation.  The Czechs that copied the Meg to some extent, went way over the top as they improved many of the features, and have clever ideas like the twist lock / push button easy remove DSV hose fittings.  This makes it easy to check DSV flappers.  The BOV (Gonad Gear Shrimp) is still the best on the market.  And I give praise to the Thorntons for wanting to develop their own electronics.  As much as I revere the Shearwater electronics, the HH / XCCR NEEDS to stand apart and stand on its own platform, and that means their own electronics.   

Accoridan CCR's  0 of 10

If a rebreather looks more like an "Accordian" inside and not a simple assembly of what looks like reasonable scuba parts put together, then run - dont walk away!  There are plenty of bars in Wisconsin where I can Polka most nights while having a beer and enjoy a gypsy playing an accordian as I don't want to own one!

The last word....

​And if you believe that, then I have a few CCR's that I would like to sell you...    CCR's can be great tools if you respect the rules of Always Know Your Po2, Always build a CCR with a Check List, Always Do Pre Dive Checks, and then you may have a safe and fun dive.

When you are looking for a CCR, have a reasonable "high" budget and don't be cheap! 

Consider what rebreather your fellow divers are diving as Support is important when you are learning a new complex tool is.  They are incredibly easy to dive, but the habits that good CCR divers express are sometimes unique to each CCR.  As well as having buddies to ask those questions of "Why does it do this or that?"  .   A CCR community with similar units is important, plus access to an instructor who is also a Mentor that keeps you engaged as that is where you will really learn. 

Spend the Time and Money to do more than one CCR demo.  When you do ask to participate in building the units so you can have "hands on" experience.  At this time one of the most important things to consider is the "Simplicity" of design.  Beware that there are convoluted CCR designs that incorporate "Bellows".  If the rebreathers you are diving looks more like an accordion,  than an assembly of scuba gear you need to run and not just walk away.....

Good diving and be safe