Question CCR for recreational depths

[Snusmumrik]

What is the bailout needed for a 50’ open water dive?

S30 is enough to ascend and stay safety. IMHO.

 

[Snusmumrik]

I guess I'm not in on the joke. Wibble can't be for real.

If someone actually wonders. One 12l standard euro tank is about 30 lbs/14 kg plus valves, BP/wing etc.
A 12l set of doubles is not 45 lbs/20 kg heavier than a rebreather.

I'm out, don't wanna deal with this nonsense anymore. If y'all wanna believe in some comic book future fantasy tech, have at it.

Lighter doubles often resulted in more lead weights carried to sink all this bubbling stuff you wear on.
For me - typical weight of 12l doubles-equipped diver is 10-12 kg heavier than same diver with rebreather. Even with b/o.

 

[L13]

berndo:

What is the bailout needed for a 50’ open water dive?

Nevermind, just go without.



That's dangerous, stupid and against all best practices.

Do you actually dive when you're not trolling?

Doesn't dive. No diving where he is located. See his profile. (but he loves to question the legitimacy of other peoples comments based on their dive history/location)

 

[Angelo Farina]

I said… “ Why dive CCR and what are the benefits?”

Care to clarify that?

An open circuit twinset is considerably heavier (65kg+) than a rebreather (~45kg) +10kg bailout.

Or deeper, 60m/200ft requires two ali80s on both systems, so OC is still 20kg more.

Or how about not carrying twinsets around for refills— CCR uses 3 litre tins and you can easily get two or more dives from one fill. 100kg extra needed for two days of diving on OC

???
My Technisub Aralu twin set weights 24 kg. It features that fantastic spring-loaed reserve, which ensure no risk of getting caught OOA, even if you forgive to watch your SPG.
Having such a nice air tank was one of the reasons for which I gave up using a CCR for recreational shallow dives.
Amd I see no reason for coming back...
I understand using a CCR for deep technical dives with Helium.
But frankly, for normal dives at less than 40 meters with light deco (so still fully recreational) my lightweight twin tank is perfectly adequate and providing me with plenty of dive time, limited by duration of deco stops, not by lack of gas.

 

[CT-Rich]

I guess I'm not in on the joke. Wibble can't be for real.

I'm out, don't wanna deal with this nonsense anymore. If y'all wanna believe in some comic book future fantasy tech, have at it.

Go back and read Shadow Divers. Look at what they were doing in the early/mid 1990s and compare it to what is going on today. It is a completely different world today. No one today would dive the u-who on air, and rebreathers would be the go to gear. Today they would identify it with side scan sonar, and drop a tethered drone on it before even considering getting in the water, all is consumers accessible gear today. And just to get to the site they would have used Loran-C to get there.

Three people died trying to identify the U-who. Today they run charters to it. I don’t think we have hit the apex of diving yet.

 

[Wibble]

Just weighed a flat-bottomed Euro 12 litre steel twinset (now used as a gas bank). This was 39kg and isn't full, call it 40kg full.

To that add:

• 2 regulators, longhose, SPG (4kg)
• Lead V-weights (5kg)
• Stainless backplate and harness (4kg)
• 1 litre drysuit inflate + regulator (3kg)
• Umbilical torch and battery (3kg)
• Wing (1kg)

Total: 40kg + 20kg ~= 60kg / 132lbs
OK, 60kg is not 65kg

An ali80 with gas, valve, rigging and regs is ~20kg. Two of those takes the OC splash weight to 100kg (plus drysuit, undersuit, fins, lift bag, crowbar, SMBs, reels, etc...).

Splash weight for CCR is (45kg + 2x20kg) = 85kg (slightly less for the bailout gas...)

Carry weight of the OC rig to the boat for two days of diving = 2 x twinsets, 4 x ali80s.
OC for a week's boat diving must factor in getting the cylinders refilled.

Carry weight of the CCR rig to the boat for two days of diving = 1 x CCR, 2 x ali80s.
A CCR for a week's diving means adding a couple more 3litre dil and oxygen cylinders, a top-off for the suit inflate and some sofnolime.

 

[TOMWIEDEMAN]

So this is a curiosity question. I had the chance to use a R1 O2 rebreather the other day in a try it dive at local pool. It was a pretty cool experience and it prompted a question. Would one of these rebreathers be able to replace my conventional OC scuba for diving at recreational depths?

Here is my situation. I typically dive with a steel 120 and most if not all my diving is above 100'. I am getting older and father time is catching up with my back. at some point I will no longer be able to sling all the lead and steel. The CCR is much lighter than a traditional OC system.

I understand that because of the PPO of a pure O2 diving is limited to 20' and repeated prolonged O2 can have an effect on your lungs. But I heard from the guy doing the try it dive that the rigs can be modified to use air as a diliuant and work at greater depths.

My question is would this be a viable option? With a upgraded DR1 would it be a viable way to dive within recreational limits? With a system like this would it a kin to breathing Nitrox at a fixed ratio or would it would the gas blend be adjustable like used in other CCRs? This is mostly an academic exercise, but I would not mind being able to go out on my usual underwater bumbles, which normally range from 30-60 FSW without having tank pressure as my limiting factor.

Just a heads up for anyone considering rebreathers. There is a lot to know and understand and its nothing yo enter into lightly. Mel Clark is an amazing source for information and probably o ne of the best instructors on the planet. Her informative and easy to understand manual should be your first step. You probably need to search the internet to find her or the manual. She is a TDI instructor and lives in Seattle, Washington, USA. WWW.silentscuba.com; Email-Scubagrunt@gmail.com; Flyingcash@gmail.com.
Good luck and happy diving

 

[Marie13]

Mel’s book is available from DGX. I found it very helpful. It was certainly better than the generic CCR eLearning TDI has.

 

[grantctobin]

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Just a heads up for anyone considering rebreathers. There is a lot to know and understand and its nothing yo enter into lightly. Mel Clark is an amazing source for information and probably o ne of the best instructors on the planet. Her informative and easy to understand manual should be your first step. You probably need to search the internet to find her or the manual. She is a TDI instructor and lives in Seattle, Washington, USA. WWW.silentscuba.com; Email-Scubagrunt@gmail.com; Flyingcash@gmail.com.
Good luck and happy diving

You might wish to revisit some or more of the statements in that post.

 

[TuckerIdaho]

And just to get to the site they would have used Loran-C to get there.

GPS was a thing in 1991.