Thoughts on dive soft liberty?

[tbone1004]

@stuartv
I'd say you have the "traditional" style, which is Meg, APD, JJ, X-CCR, Hammerhead, Poseidon, etc. Subsets of that will be the counterlung configuration since most of those can be bought in different counterlung configurations but the lungs all work the same way, so do the units. O2ptima is kind of in its own world
After that you'd have the "all-in-one" configurations like the SF2, KISS Sidekick, RB-80, etc. that also function basically the same. RB-80/SF2 with bellows, and the Sidekick inside of the lung, but it's basically the same thing
Then the Revo is in it's own world.

You can bring them down into sub categories depending on your specific purchasing requirements, i.e. mccr vs eccr, divecan vs others, bmcl vs ots, etc.

 

[rjack321]

The liberty and any kiss seem like pretty much polar opposites to me.
The liberty has almost the maximum amount of wiring short of adding revos RMS and a xccr CO2 sensor. The helium sensor is certainly unique.

The kiss can be run off a single, long since obsolete but still functional, shearwater predator and no other wires/wiring at all. No solenoids, no RMS, no CO2 sensors, no helium sensors, no 4th and 5th cells. Not even a secondary display is required.

 

[broncobowsher]

I'm pretty sure the KISS can be run even simpler, just a PPO2 monitor or two (or three). No computer at all.

But I believe you are correct, not even a rEvo with RMS can compare to as complex as a Liberty is.

Even the Poseidon is rather complex with the automated self test it does.

 

[ChuckP]

You say the Liberty is complex but doesn't it just really have two controllers verses one, in like comparison to a JJ say - I understand the PO2 is handled with 2 cells plus the He sensor but isn't it really just two working together but redundant sides??

 

[Sifossifoco]

isn't it really just two working together but redundant sides??

I know very little about the Liberty, but it would seem to me that if the two sides have to 'work together', then there is no real redundancy, and if they are working independently but at the same time, then there is the need for a voting logic in case of failure of one of them.
Each side has two O2 sensors, and I believe that only Poseidon uses a validation algorithm with two sensors, main and secondary. I suppose the two sensors in the Liberty are either validated against the two cells on the other side (then no redundancy) or using the He sensor somehow, and that would be an original validation strategy.
It would interesting to know more.

 

[stuartv]

The liberty and any kiss seem like pretty much polar opposites to me.
The liberty has almost the maximum amount of wiring short of adding revos RMS and a xccr CO2 sensor. The helium sensor is certainly unique.

The kiss can be run off a single, long since obsolete but still functional, shearwater predator and no other wires/wiring at all. No solenoids, no RMS, no CO2 sensors, no helium sensors, no 4th and 5th cells. Not even a secondary display is required.

If I cared to, I could certainly run my rEvo with just its Predator and no solenoid, no rMS, and as few O2 sensors as I wanted - even 1, if I were that foolish. No ADV even. And certainly no CO2 or He sensors. I could even run it with no Predator, and just a rEvo Dream or 2, and a set of Constant PO2 tables for dive planning.

Or I could ditch the Predator with all the rest and just run it with just my NERD, which has a direct analog connection to its own O2 sensors. No solenoid, no rMS, no DiveCAN. As few O2 cells as I choose. Just an analog computer monitor, a MAV block, and a CMF to save me hitting the MAV button as often.

I ran it with no solenoid for almost a whole dive on the Jodrey a couple of months ago when it turned out that the wiring to the solenoid had gotten corroded inside the insulation to the point that a brand new battery only had enough voltage to run it for about 15 minutes before the voltage dropped enough to no longer be able to fire the solenoid with all that extra resistance in the circuit. I noticed the ppO2 dropping before it dropped below 1.1 and flew it manually for the rest of the dive. No big deal.

The solenoid, the rMS, the NERD2 monitor, and the extra O2 sensors just add to my margin of safety. I.e. they allow me to screw up to a greater degree before I pay any real price.

 

[broncobowsher]

You say the Liberty is complex but doesn't it just really have two controllers verses one, in like comparison to a JJ say - I understand the PO2 is handled with 2 cells plus the He sensor but isn't it really just two working together but redundant sides??

What I remember from a few years ago...
2 separate controllers. One is controlling, the other is just sitting back watching. 2 O2 cells in each.
If one cell goes wonky in the active controller side, that controller senses the error and quits being the controller. The other controller with 2 good cells is now in charge. So a fault in any one cell will sideline the controller attached to it, but the other controller with two good cells still goes on. Pretty much the same as if you have 3 cells and one goes wonky, it's value is discarded and the 2 good ones are used. Just you are doing it with 4 cells instead of 3. But there are 2 separate controllers instead of one, but they are not exactly completely separate since they do have to talk to each other. I forget the part connecting them, but it is a Liberty specific piece and there are reports of it failing making neither controller functional. Dead just like a single controller rebreather failing a controller.

 

[jmorgan007]

The bright shiny advertising they do doesn't hurt either - by that I mean all the informational videos they have on their website - most other companies have virtually zero.

Just trying to read between the lines and see if the bright shiny stuff is a cover or real.

In my opinion Divesoft has done a lot to be very open with their potential new and returning customers having published the Divesoft Liberty in depth video series. It communicates at a very high level of detail their design language and capability to educate potential customers on their system configurations. This speaks volumes as to how focused as a company they are to supporting their customers. They understand it's a hard market with a lot of front end technical details that need to be presented.

You already stated the obvious the competition doesn't even have enough respect for their potential customers to be as open and revealing of their CCR offerings with such an in-depth rollout of their rebreather systems. At least from my finding having researched YouTube for the past year and a half as it's Feb 2024 currently. For the love of God a majority of the potential customer base has zero access to just drive down to their local LDS and get a hands on view of even one CCR unit let alone a variety of them to get a hands on comparison with a knowledgable staff that can present what hours of Divesoft Liberty YouTube series has provided. It builds a heap ton of confidence in understanding the design language options of the system and also eases the stress level for a potential ordering process. It gives the shopping client the ability to mentally map out cost and design from the start what equipment they need for their intended dive applications instead of wasting money listening to what the local shop sells or the local dive community are diving. To all this I see heaps of value and say thank you Divesoft you have done extremely well on this and with my dealings with the company have received nothing but stellar customer service.

Shop the unit first to meet your dive needs. You're looking to buy a $10k unit and it remains with you. Your instructor likely at distance will come and go. It's been said before, unit first to match your dive needs then source the best instructor you can for the unit. It makes a hell of a lot of sense to the educated owner operator. If your an informed diver you should know why you want an expensive rebreather in the first place and not everyone in your local area may be using it for he same purpose you want to use it for. So just because brand X is down the street doesn't make it the best choice for all. If you happen to have a lot of financial means and just looking to do something new and challenging then this may work for you to go with what the locals run. However if you are focused for a very specific reason for example your not going to purchase the new Ford electric pickup if you need to head out in the back country and do some real serious mission critical work at distance and need a fast refueling at the service station anywhere. Develop an understanding for your needs first then get the model that supports that, the instructor base will become evident from the small hand full of options available as rebreather instructors are few and varied these days likely for any specific model being able to be counted on your fingers and toes meaning for a lot of people you will be trading at distance from your home site for certification training.