Question SCR Semi Closed Rebreather

[Angelo Farina]

The only semiclosed rebreather I used is the Caimano IV SCS by Siel:

Rebreathers – Siel

www.sielnet.com

This is a military grade purely mechanical rebreather which can be operated in two different ways:
1) CC pure oxygen (ARO)
2) SC pure Nitrox
For this second operational mode you must wear a pair of small back-mounted Nitrox tanks.
In SCR mode you get a constant supply of Nitrox flowing into the counterlung, while a manually adjustable silenced exhaust valve purges out the same flow of Nitrox which is flowing in, keeping the volume (and the buoyancy) invariant.
The tactical advantage of this unit is that it allows for much larger depths than a pure-oxygen CC with less weight and longer duration than a standard OC scuba system.
Being a military grade unit, and having been involved in its design and testing, I cannot say more.

 

[lostsheep]

Air makes sense for us old-style recreational divers who are certified down to 50m and with deco on back gas.
For depth ranges between 40 and 50 meters (which is the best range here in the Mediterranean) and with deco times of no more than 20 minutes, a single 15-liters tank at 232 bars filled with air, with double valves, two independent regs, and perhaps a good old reserve, is all that you need.
For shallower depths and within NDL Nitrox makes more sense.
Air comes handy again for hookah diving at less than 10 meters.

I am not going to pretend that I haven't been deep enough on air to narc me out, nor will I say unequivocally I won't do it again.

What I will say is that if I have the choice, I will avoid it.

Everyone has to make up their own mind about how deep they think they can go before narcosis is concerning to them. I have my own answer, I don't have yours.

 

[kensuf]

Late to the party...

I see these every now and then at Blue Grotto, so they're out there.

Horizon Rebreather - SCR - Mares

Horizon rebreather: incredibly extended dive time. Revolutionary SCR approach in a system that is easy to use, natural to dive, designed with all levels of diver. Discover more on Mares.com

www.mares.com

 

[Dave1w]

You can do SCR if you want. I'm not sure how many of those commenting started out on Dragers, but they are an option. I picked up two units for £500, with enough bits to make at least one good one and a project. Easy to clean and repack the scrubber, and pleasant enough to dive. Cheaper than a cheap CCR ( you can no longer get a cheap kiss to start on, and a cheap inspo is a lottery) or go with an inverted twinset with nitrox, so you can reach the valves. none of it is rocket science.

 

[sylverbard]

Welp, that's exactly why I asked my question of how much work. I definitely do not have that time right now, I have a toddler and hoping for a second one in the near future.

This thread has definitely been a valuable learning experience for me. The dream of one day getting a ccr is still there but the reality is that I'm most likely 5+ years away from even really considering getting one.

Toddlers go on a leash clipped to your butt d-ring. no effect on filling scrubber material at all.

 

[Dann-Oh]

Toddlers go on a leash clipped to your butt d-ring. no effect on filling scrubber material at all.

That's my problem, I don't have a butt d-ring.

 

[rmssetc]

Toddlers go on a leash clipped to your butt d-ring. no effect on filling scrubber material at all.

Do you sidemount your toddlers? That's a good choice if they are different sizes, but if they are twins then rigging them as doubles works well. If they are Siamese twins you don't have any redundancy.

 

[sylverbard]

That's my problem, I don't have a butt d-ring.

I can fix that. $800.00 Canadian plus shipping.

or just use right side hip d-ring.

 

[sylverbard]

Do you sidemount your toddlers? That's a good choice if they are different sizes, but if they are twins then rigging them as doubles works well. If they are Siamese twins you don't have any redundancy.

never. different sizes, different buoyancy characteristics, and unwelcome sudden propulsion bursts.

 

[mr_v]

You can do SCR if you want. I'm not sure how many of those commenting started out on Dragers, but they are an option. I picked up two units for £500, with enough bits to make at least one good one and a project. Easy to clean and repack the scrubber, and pleasant enough to dive. Cheaper than a cheap CCR ( you can no longer get a cheap kiss to start on, and a cheap inspo is a lottery) or go with an inverted twinset with nitrox, so you can reach the valves. none of it is rocket science.

I've been monitoring Drager listings on eBay and support this idea. $1K will get you a unit in mint shape.