Question CCR for recreational depths

[MidOH]

Agree, but four minutes not paying attention to your CCR while it's flashing red in your face? Maybe one should pick an other hobby? To me there no valid reasons for not paying attention to the CCR. If you're too busy, bail out and go OC just to be save. A CCR requires you to pat attention all the time!

I know there have been fatalities and yes, I know the risk on the surface is greater. But you have to realise you're not diving OC. The adagium here is: know your ppo at all times, no matter what. The lesson learned in most accidents is lack of attention or/and complacency. Very few accidents can be attributed to mechanical failure.

This.

If we get past, that you have to watch the ccr, and that po2 shifts more during shallow depth changes,

.....is there anything else bad about a ccr within rec limits?

 

[broncobowsher]

This.

If we get past, that you have to watch the ccr, and that po2 shifts more during shallow depth changes,

.....is there anything else bad about a ccr within rec limits?

I will say there is one more bad thing about shallow CCR. Buoyancy is harder to maintain in the shallow side of diving. Open circuit you can make minor adjustments with lung volume. CCR that doesn't happen. In deeper water, a minor change in depth doesn't really affect the overall volume of air you are breathing (lungs+counterlungs). While in shallow waters a small change in depth has a larger change in gas volume.

It is common to do 20' deco stops on CCR where OC will do 10'. OC on 10' will conserve more gas, you can stretch out your deco bottle. 20' on CCR is easier to maintain the depth. Being CCR and on (nearly) 100% O2 you still get (nearly) the same deco at 20' as you would at 10'. The difference is 20' is a lot easier to hold than 10' on CCR.

 

[inquis]

is there anything else bad about a ccr within rec limits?

See numerous things up-thread (COST, heavier going up the ladder, setup/breakdown time & necessity, etc.) The primary benefit within rec limits seems to be the lack of bubbles.

 

[Wibble]

Just know that your rebreather is trying to kill you. It might be working now, but it'll bide its time and kill you later.

Complacency kills.

Just act accordingly and you'll be fine.

 

[tursiops]

This of course depends strongly on the region. Here in the Mediterranean, and particularly here in Italy, CC pure-oxygen rebreathers (ARO) were the standard scuba equipment for diving in the fifties and the sixties. Compressed air systems were much more expensive, bulky, providing shorter diving times. They were reserved for professional divers hunting coral, for example.

I worked at a NATO oceanographic lab in La Spezia 1968-1972. There was not a lot of diving at the lab, but what there was was done with steel tanks and compressed air. I never saw a CCR, pure-O2 or otherwise. The diving was done by Italian Navy folks who also were lab employees. The only other diving I saw in Italy during those times was on Christmas Eve in 1969 in Tellaro, when a new tradition was begun with scuba divers arriving on shore at midnight carrying a Christ child doll. Those divers also wore tanks, not rebreathers, I'm pretty certain.

 

[rddvet]

Just know that your rebreather is trying to kill you. It might be working now, but it'll bide its time and kill you later.

Just act accordingly and you'll be fine.

I wish people would stop saying their ccr is trying to kill them. It’s overplayed and inaccurate. Let’s move on from this far too often written bs
Being complacent or getting poor training is what’s trying to kill you.

 

[rob.mwpropane]

Rebreathers are most definitely not for people who throw their kit into a heap and leave it.

Dammit!

 

[ND5342]

See numerous things up-thread (COST, heavier going up the ladder, setup/breakdown time & necessity, etc.) The primary benefit within rec limits seems to be the lack of bubbles.

Could be less weight if longer dives are desired and less cylinders needed to be brought to the dive site. No changing tanks in between dives.

 

[ND5342]

Just weighed my RD1 rebreather 41lbs. Mind you that is no sensors, MAV's and hoses or a computer/ PO2 monitor. Steel full 120s would be around @50lbs. I think once I added short 19s and all the above equipment I would be at @50lbs as well. Again this of course would just be for dives up to 60 FSW. Anything deeper than that and like most manufacturers recommend you are going to need seperate bailout.

 

[OTF]

Just know that your rebreather is trying to kill you. It might be working now, but it'll bide its time and kill you later.

Complacency kills.

Just act accordingly and you'll be fine.

I wish people would stop saying their ccr is trying to kill them. It’s overplayed and inaccurate. Let’s move on from this far too often written bs
Being complacent or getting poor training is what’s trying to kill you.

The poor thing is trying its best to keep you alive, it's just really really bad at it.

And don't pretend they're not. Sure they can be dived safely, but they come nowhere close to the level of safety and reliability we are accustomed to in the other, more highly developed safety-critical products we interact with on a daily basis (cars, planes, OC rigs, medical equipment, appliances, etc.).