DIR- Generic Doubles Gas Management?

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OP
buildhuntcook

buildhuntcook

Registered
Messages
15
Reaction score
9
Location
Columbia, Missouri
# of dives
50 - 99
I am newly interested in moving into back-mounted doubles and looking into the different systems. I have talked with several advanced technical as well as cave divers and I have a newby question about how the gas is managed on a set of back-mounted twin cylinders. Everyone in my local area uses a long hose configuration, i.e. GUE/UTD/ISE with a manifold. I went to a PADI shop looking into tech courses as they are the only ones that offer technical courses in my area (the advanced divers in my area were trained elsewhere) and now I am really confused about how to breathe from back-mounted doubles. From what I can gather the manifold is open all of the time and the tanks are breathed down as if they were one big tank with a really large volume. The primary regulator stays in the mouth all of the time. If there is an issue then the appropriate response to find/shut down the problem is addressed. The PADI guys I talked to described using the back-mounted doubles basically as two independent systems and requiring redundant EVERYTHING. They described breathing down each tank 500 psi and then switching regulators and leaving the manifold closed and shutting off each tank. Is this the correct method according to PADI? I feel like this defeats the purpose of the manifold being able to share gas with each regulator. The introduction of redundant everything in my mind would make it much harder to find a problem. If you have a redundant bladder in your BC and it auto-inflates then the diagnosis is more steps than knowing your bc is inflated from just your right post. I asked what they did in the event of a buddy being out of gas and having to donate if the valve was shut every time they switched and they said you turn it on. If there is an event on the regulator you are breathing from then equalizing the pressure across the manifold introduces high pressure at depth that could potentially cause more problems. Am I just way overthinking this? Is this the PADI approach to technical diving? Again I am new to this journey and I just want to feel confident about the place I am going to seek training. Any advice or experience is greatly appreciated.
Thanks in advance
 
@buildhuntcook Assuming we’re talking about Columbia MO, there is one very local Cave 2 Tech 2 diver within a few miles of you as well as a few people within OCDA that could likely put you on a smoother path
We are talking about Columbia, MO. Any information you could pass along would be extremely helpful. I am relatively new to this area and with corona and all that have just barely started getting involved with the diving community. My LDS are wonderful folks and they are looking into finding ways to get more programs going but that seems like a ways off and they are not technical focused.
 
Here’s the list of US based instructors:


I’d reach out to a couple to see their availability and pricing.

I took Tech 1 from Guy Shockey he’s a great instructor and does travel, he might be a bit on the expensive side for a fundies instructor though as he’d have to travel from Canada.

There’s a good sized GUE community in the Pacific Northwest, especially in the Seattle area.
Thanks! I really appreciate it.
 
I get that. I am working towards becoming a dive guide and master diver is literally just a stop on the way to that.

Ok, just seemed like from your post you were deciding between the two. I just got “master diver” but like you said it just happened because i I took the right number/ needed courses and had enough dives through SSI. Wasnt trying to get the “rating.”
 
Ok, just seemed like from your post you were deciding between the two. I just got “master diver” but like you said it just happened because i I took the right number/ needed courses and had enough dives through SSI. Wasnt trying to get the “rating.”
That is exactly my thinking. I grew up in Guam in the early 80s and was taught to dive with gauges, tables, and a watch. My dad gave me some old tanks and I went to have them looked at and couldn't get them filled without a certification. I figured if I'm gonna pursue certifications I might as well try to offset some of the cost by becoming a guide/AI/OWDI. I basically pay for the courses to travel and have dive buddies.
 
We are talking about Columbia, MO. Any information you could pass along would be extremely helpful. I am relatively new to this area and with corona and all that have just barely started getting involved with the diving community. My LDS are wonderful folks and they are looking into finding ways to get more programs going but that seems like a ways off and they are not technical focused.
You have received some great info.

I am a couple of hours South of you. If you make any trips to Table Rock or Beaver, give me a shout.

I dive Stockton and the two lakes above most every Sunday and Monday.

DW
 
I currently dive freshwater lakes, springs, and quarries in the midwest. Low visibility and cold thermals. I grew up diving in Guam as I stated above. I am extremely comfortable in the water. I am pursuing wreck penetration. My wife said that if I pursue cave diving then I will be single lol(she watches a lot of crazy videos). She doesn't understand there are plenty of similarities between wreck penetration and cave diving, but that's ok with me. I will be moving to the Pacific Northwest next year so it will be a lot of cold water diving up there. I am willing to travel and invest in quality training.
Then don't tell your wife that wreck diving is inherently more dangerous than caves. Because caves usually don't change or collapse overnight. Wrecks do that all the time.
Diving with doubles is normally treated as one big single with the option of isolating one cylinder in the event of some type of failure. I taught tech classes for 10 years and had students travel to me from all over the east coast.
And I've had students take classes with me and then on my recommendation travel to Florida to train with someone else when I wasn't able to offer them a warm water option.
Tech should not be rushed into. Saving your money and spending an extra grand or two to travel to work with a good instructor may save your life down the line.
 
I had not considered having an instructor travel to me. My dive buddy is the only person I have met in the area that is interested in advanced diving. I am interested in GUE and like the idea of having a unified system among your dive buddies. It is hard to convince a certified dive buddy that we should spend $1500 on a fundamentals course when we could become master divers for $1000. I understand the quality of instruction is better and the GUE course probably covers the five courses worth of material. I want to have a really solid foundation with confident and competent dive buddies, there is just not a GUE presence where I live. Do you know of an instructor that would travel?
If you're interested in GUE, then take fundies and decide if you want to continue with GUE. I thought I knew alot about doubles until I started tech 1 and learned I didn't know doubles and their failure modes nearly as well as I thought I did.
 
You have received some great info.

I am a couple of hours South of you. If you make any trips to Table Rock or Beaver, give me a shout.

I dive Stockton and the two lakes above most every Sunday and Monday.

DW
Hey DW, it looks like Stockton lake is a little under three hours from me and Table Rock is about three and a half. I am headed to Mermet this weekend but am definitely interested in heading down there for a day trip or overnighter at some point. I typically hammock camp when I go down to Bull Shoals. Do you know if there are any primitive camps around there? I am trying to get as many dives in before the water turns frigid as I haven't invested in a dry suit yet. My email is buildhuntcook@gmail.com if email is a better format for you. I appreciate you reaching out!
 

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