Is the Mk VI / SE7EN really that dangerous

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Remotely related to the topic...
Are there any public figures regarding the popularity of different rebreathers worldwide?
Total number of units sold by each manufacturer is probably what I am looking for.
No TDI did a graphic of certs by unit but it was only for them and not representative across all agencies. AP, revo, meg and kiss are perhaps high on the list but they have been around far longer than Poseidon's CCR offerings too

I could never deal with a Poseidon's course requirements, but then again one of my units is a kiss which couldnt be more opposite.
 
I could never deal with a Poseidon's course requirements, but then again one of my units is a kiss which couldnt be more opposite.

Does it differ from other units anymore? Leaving the "recreational rebreater" stuff aside, it now seems that someone new to rebreathers can buy a full spec unlimited Se7en and follow the same training path (i.e. TDI) with other rebreathers?
 
@RainPilot thank you so much for your input into the unit, most of what I read in the manual is now clear following your explination. If not for this embargo I would have dearly liked to come and train with you but travel is now susch a pita to get there.
 
@RainPilot thank you so much for your input into the unit, most of what I read in the manual is now clear following your explination. If not for this embargo I would have dearly liked to come and train with you but travel is now susch a pita to get there.
Embargo? I must be out of touch... I have SA folks come out here often. Unless, you are working at the neighbours?

Barry Coleman is in SA, he was involved in the original design phase of the Poseidon, along with Bill Stone and Richard Pyle and others.

Rebreather Diver Training - Meridian Dive Centre
 
I'm in Qatar, stephchild of the GCC lol.
Well, if you find a way to get here, I will happily take you for a Poseidon trydive or whatever. Doha-Turkey-Dubai seems to be a popular choice for expats these days.
 
I'm not sure if this was covered, but how many sensors does the unit have? Any less than three and it's a no go for me, solid state or not.
 
I'm not sure if this was covered, but how many sensors does the unit have? Any less than three and it's a no go for me, solid state or not.
It has 2, 3 is only useful if voting logic is implemented. There are some fundamental reasons why 2 can be better than 3, especially in a calibrated and monitored scenario.
 
As to the tank thing, I physically cannot mount my tanks to either of my units incorrectly and have them physically connect where the required connections are. This is possible with the Poseidon?

Think about inline valves and think about using camstraps as mounting equipment. JJ's, AP's and I'm guessing Poseidon's love inline valves, our SF2's don't.
 
It has 2, 3 is only useful if voting logic is implemented. There are some fundamental reasons why 2 can be better than 3, especially in a calibrated and monitored scenario.

Not true, an extra cell is 33% more data with which to make a decision, regardless of whether or not the electronics utilize It to make addition decisions. The issue with two cells is that the only calibration and monitoring is against a single other point of failure. It’s the same argument Andy Davis uses with the stock Pelagian, and falls apart because of the same reasoning. With 3 cells you can easily determine which of any 3 cells has an issue, or even if multiple cells are faulty. With only two, even monitored and calibrated, you’re counting on the other being fully functional as well.

Think about a frozen pitot tube affecting airspeed and an autopilot system, and that’s got substantially more intelligence backing it up. Not the best analogy, but if you only have one other comparative measurement to which you can reference, it’s easy for the calibrated and monitored system to fail. Adding a third point of reference allows you to check either of the other systems, as well as the system as a whole. The problem with the rEvo’s using a bazillion cells is you start introducing a fairly substantial number of failure points since you need an odd number to rule out any “tie.”

The idea that the system can do the math for you with two cells is fine until it runs into a situation where it cannot make a reasonable determination. With a third cell it would allow for a more failsafe reference.

Ultimately it comes down to trusting the machine. A calculator is better than the brain until you give it an illegal operation. And in the same way I’d fly with a G1000 glass cockpit, I wouldn’t rely on my little eTrex to fly IFR. There’s a substantial difference in the machines, and I don’t think Poseidon is the “autopilot” of the rebreather world yet.
 

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