Question CCR for recreational depths

[L13]

Sofnolime in US ~ $200 per 20kg keg.
Average scrubber size 3kg, 20/3 ~= 6
$200/6 = $33 per Phil

Max time on scrubber... In the CE anyway ... 3h.
So $11/hour for lime.

Plus oxygen at about 1.2 litres/min = 50 litres/hour


(Obviously if it were a Revo it would be 5h per 1.4kg Sofnolime, so 14 fills = $14 for 5 hours...

Per the Sofnolime spec sheet, it absorbs 150 L/Kg of CO2. CO2 is produced at the rate O2 is consumed, so 3 hours/Kg. or $3.33/hour. O2 fill around here is $15, so 3L cylinder at 250 bar is $1.00/hour. (both assuming 50 L/hour O2).

Less than $5 per hour total.

Initial cost would drop in volume. The RD1 Rebreather which restarted this thread goes for $2K + BPW setup now, and would be even less in volume.

The limiting items (assuming volume) are training, and attitude. @Angelo Farina is always bringing up the fact that many decades ago an O2 only rebreather was the standard recreational setup in Italy, so those aren't deal breakers either.

Not happening soon, but not beyond the realm of possible in the future.

 

[L13]

Interesting diving this Saturday. 12 divers on a boat with 11 diving all sorts of rebreathers; only one diving with a twinset. The dive to a mere 28m/95ft.

Only five years ago that would have been a majority or most on open circuit.

What was the mix of rebreathers being used?

 

[Wibble]

What was the mix of rebreathers being used?

Think it was:
6 AP Inspos
2 JJs
1 Meg
1 Prism
1 Revo

 

[Wibble]

Per the Sofnolime spec sheet, it absorbs 150 L/Kg of CO2. CO2 is produced at the rate O2 is consumed, so 3 hours/Kg. or $3.33/hour. O2 fill around here is $15, so 3L cylinder at 250 bar is $1.00/hour. (both assuming 50 L/hour O2).

Less than $5 per hour total.

Initial cost would drop in volume. The RD1 Rebreather which restarted this thread goes for $2K + BPW setup now, and would be even less in volume.

The limiting items (assuming volume) are training, and attitude. @Angelo Farina is always bringing up the fact that many decades ago an O2 only rebreather was the standard recreational setup in Italy, so those aren't deal breakers either.

Not happening soon, but not beyond the realm of possible in the future.

The $64k question for this is... How do you know when your scrubber's exhausted or even working?

(Temp sticks -- that measure if the scrubbers are working -- are only available on a couple of boxes; AP and Revo)

 

[L13]

Think it was:
6 AP Inspos
2 JJs
1 Meg
1 Prism
1 Revo

Interesting! That is not the distribution I would guess from SB posts.

 

[rjack321]

The $64k question for this is... How do you know when your scrubber's exhausted or even working?

(Temp sticks -- that measure if the scrubbers are working -- are only available on a couple of boxes; AP and Revo)

temp sticks, 5 rotating cells and 2 rotating scrubbers all the magic!

 

[grantctobin]

temp sticks, 5 rotating cells and 2 rotating scrubbers all the magic!

And all the “logic”!

 

[grantctobin]

Interesting! That is not the distribution I would guess from SB posts.

While having an international presence, SB is still US centric. The above distribution would be uncommon outside of the UK or a couple specific areas (e.g Inspo dominates a few scientific diving groups).

 

[CT-Rich]

I started this thread to take the temp of where the rebreathers were at relative to open circuit. I think the very long projections on CCR becoming mainstream is going to happen a lot faster than many think. The first step is to make them reliable and moderately idiot proof. There is a ways to go on that, but it will come.

The big breakthrough will come when dive resorts start offering them as an option. and regular divers get to go on dives where they are engaging sea life with no bubbles. Watching sharks, turtles, seals etc. with no bubbles to spook the animals. Divers will go home and start shelling out money for them and reserving them on trips. The big dangers of them will be the ability to screw the pooch on deco. One of the saving graces of the traditional Al 80 is that most newbie divers can't stay down on an 80 long enough to get seriously into a serious deco obligation.

There was a time when everyone would think that mixed gasses were to complicated for the masses. Nitrox is almost ubiquitous and dive computers have pretty much made it idiot proof. Some types of diving with mixed gasses are still very technical with a limited appeal, but recreational diving with nitrox is no big deal.

I could see some variation of CCR becoming widely used by recreational divers. Technology will find a solution for the question of how to monitor CO2 scrubbing and make it pretty safe for all but the least competent of divers. Charters will start splitting off for the rebreather only excursions and those for open circuit crowd. I am pretty sure that is already true for some places.

 

[rjack321]

Interesting! That is not the distribution I would guess from SB posts.

The revo divers outtalk all the other CCR owners combined, although the sidewinder divers are a close second at least on FB