???Future of Open Circuit Mixed Gas and Rebreather Diving???

[BlueTrin]

Tech 1 is a prerequisite for GUE ccr1.

When gue ccr1 is finished max depth is 30 meters / 100ft and no deco.

Deeper dives and deco are permitted once 25 ccr dives have been completed (maximum depth 51 meters/170 ft depth, maximum 30 minutes deco and maximum 200 minutes scrubbertime).

What are you allowed as BO and diluent?

I guess the diluent is also your BO in this config? (Asking not 100% sure) but are you also carrying a stage of Nitrox or O2 as part of CCR1?

 

[barth]

What are you allowed as BO and diluent?

I guess the diluent is also your BO in this config? (Asking not 100% sure) but are you also carrying a stage of Nitrox or O2 as part of CCR1?

The bailout for Gue ccr 1 training is EAN32. Ccr1 training is similar to Gue fundamentals with a ccr. CCR 1 training is without a stage, and only the ccr and doubles. With the gue configuration bailout in the doubles is also the diluent.

Mod for ean32 as diluent is 15 meters, mod for 21/35 as diluent is 30 meters, mod for 18/45 as diluent is 45 meters. Most divers use 18/45 for ccr 1 dives. 21/35 has never been used as a diluent by me. I did use 15/55 as diluent, but it's not easy to switch doubles or change mixes for the doubles every day when diving. I keep my doubles for my jj filled with 18/45 for ccr 1 dives because of that.

When doing ccr1 dives, I always carry a stage with oxygen or ean50. Sometimes I bring ean50 as decogas and my buddy oxygen as decogas. As long as each team member has sufficient bailout gas for their own usage. This allows us to be more flexible if there are problems during the dive.

 

[Celt]

If you take into account the amount of dives the average diver gets in, beyond 60m in a season. It’s going to take a very long time for some to make a financial saving on helium if choosing to use a rebreather over OC.

 

[formernuke]

15 meters seems shallow to me. 1.0 ppo2 for ean32 is 70 feet.

 

[Wibble]

Thus far this year have managed 21 dives over 45m/150ft with 10 over 60m/200ft, all 1h50 to 2h35.

Gas wise every dive was 50% helium or more for the deeper dives.

Using gas pressure transmitters means the gas volumes are recorded in the dive logs. All the above consumed diluent between 90 litres (30bar of a 232bar 3 litre cylinder) and 150 litres (50bar)

Assume an average of 120 litres for 21 dives is 2,520 litres of diluent consumed; about 1,300 litres of helium used.

Compare with a single twinset containing 18/45. 24 wet litres at 220bar is 5,280 litres of gas; 2,376 Litres of helium.

TL;DR
A whole season of 21 CCR dives between 45m/150ft and 70m/230ft consumed HALF the helium of ONE open circuit dive.

 

[broncobowsher]

If you take into account the amount of dives the average diver gets in, beyond 60m in a season. It’s going to take a very long time for some to make a financial saving on helium if choosing to use a rebreather over OC.

Assuming that the price of Helium and the price of a rebreather are the ONLY factors looked at. As mentioned countless times there are many more benefits of CCR.

And I sure hope you are not waiting until 60m before using helium.

 

[nadwidny]

If you take into account the amount of dives the average diver gets in, beyond 60m in a season. It’s going to take a very long time for some to make a financial saving on helium if choosing to use a rebreather over OC.

The average diver doesn't do 60m dives nor should the average diver be diving CCR.

 

[Celt]

Assuming that the price of Helium and the price of a rebreather are the ONLY factors looked at. As mentioned countless times there are many more benefits of CCR.

And I sure hope you are not waiting until 60m before using helium.

HeliAir, you’re only adding helium after 57m PPO2 of 1.4 very simple and little helium.

 

[Celt]

The average diver doesn't do 60m dives nor should the average diver be diving CCR.

That depends on where you take your averages from.

 

[Celt]

Thus far this year have managed 21 dives over 45m/150ft with 10 over 60m/200ft, all 1h50 to 2h35.

Gas wise every dive was 50% helium or more for the deeper dives.

Using gas pressure transmitters means the gas volumes are recorded in the dive logs. All the above consumed diluent between 90 litres (30bar of a 232bar 3 litre cylinder) and 150 litres (50bar)

Assume an average of 120 litres for 21 dives is 2,520 litres of diluent consumed; about 1,300 litres of helium used.

Compare with a single twinset containing 18/45. 24 wet litres at 220bar is 5,280 litres of gas; 2,376 Litres of helium.

TL;DR
A whole season of 21 CCR dives between 45m/150ft and 70m/230ft consumed HALF the helium of ONE open circuit dive.

So 10 dives past 60m and if using Heliair to maintain 1.4 PPO2 that’s very little.