Cave Diving, Cave Exploration and Cave Mapping in Yucatan, Mexico
Caver Diver at Little Brother Cenote at Chac Mool Mexico

Valve Feathering and Valve Management

I recently wrote an article detailing my Advanced Side-Mount Cave Diving Class with Steve Bogaerts. In that article I made reference to feathering my valve after a regulator failed underwater. One of my favorite readers, Anna, sent me an email asking me, “What is feathering? I mean I know your valve was leaking and I’m useless at valve drills. So I guess it means you blew a burst disc and just had to let the tank run down?” I thought I should explain and I wanted to provide a brief explanation of a systematic approach to practicing valve drills as it was taught to my wife and me.

Valve Feathering
Feathering is the act of actuating, opening and closing, the valve on a scuba tank to control the flow of gas. I originally learned the skill to deal with a stuck open solenoid on my rebreather. I adapted the skill for dealing with my leaky regulator. The idea is to limit the gas loss from the leak to extend the time you can use the tank. When done correctly, I open the valve as I start to exhale and close it before I am finished; drawing the regulator empty at the end of my breath cycle. This limits the regulator to leaking just when I am drawing gas. This same skill is a prerequisite if you ever find yourself breathing off a tank valve 3000 feet back in a cave.

The specific problem I had was that my low pressure inflator hose had loosened itself from the first stage of the regulator and was leaking from the connection. I was diving brand new Apex XTX 50’s with DST first stages. I had just assembled them, and I didn’t tighten the hose enough. I was diving side-mount and practicing bottle handling skills, so I was forced to don and doff my tanks many times that day. In the course of rotating the tanks out in front and back, the hose came loose. Of course it loosened in zero visibility and I was unable to figure out the source of the leak. Therefore, I was forced to isolate the leak by shutting down the valve and going on my other side-mount tank. Once I handled the priority emergency, being entangled and cutting the wrong side of the line, and I had passed the remaining restrictions, I switched from the fully functioning system to the leaky system. At this point, I started to feather the valve to control the gas loss and maintain the air source as long as possible.

Valve Management!
“Valve” and “Management” are dirty words in the tech diving community. I know many people who have suffered with valve management, including my wife. They all had trouble with it until they learned a logical process for executing them and dedicated time in a pool or on their safety stops to practicing.

I believe there are three primary reasons people have trouble with these skills:

  1. They can’t reach their valves.
  2. No one ever taught them a logical process and gave them the reasons for each step.
  3. People don’t practice.

The first reason is non-sense. Your rig should be configured in a way to allow you to reach your valves. If your dry suit is too tight or your valves are too low, they you have a real problem. It is a problem that may lead to your drowning. Stop diving and fix the problem. Why would you ever enter the water with a system you know if broken? It just does not make sense.

The second reason is reasonable, not everyone has an instructor that has a logical easy to remember system. My Advanced Nitrox/Deco Procedures class provided no methodical instruction on this issue other then, “Let me see you close your valves. It is ok to do it one at a time.” This is where your choice of instructions really makes a difference. It might save your life.

I am going to share with you the system Allie and I learned. Keep in mind this is for a person diving manifolded doubles with an isolator. It also assumes you are breathing off the right post to start:

  1. Close your right post first. Breathe it empty and switch to the left regulator. Why? It is the most dynamic regulator and will be prone to fail first. You breathe it to the end to confirm you have shut off the correct regulator. Switching to a regulator that is off will come as a nasty surprise.
  2. If the leak continues, turn your right post back on and turn your left post off. Breathe the left post empty and switch back to your right post.
  3. If the leak continues, shut down the isolator and try and figure out which tank is leaking.
  4. Turn on the left post and switch to the tank that is leaking. Breathe it empty then switch to the remaining tank.
  5. Open the isolator at the end of the drill.

If you practice this in the same way each time, it will go into muscle memory. It also helps to do an audible gear matching exercise, at the start of the dive, where you call out each piece of gear and touch the post it is attached to. This helps build a reflex to turn off the correct post in the event of an easily identified leak, such as a leaky SPG. As you become more proficient, you can start to close the isolator at the same time you close the post. I would suggest the first couple of times you practice, have a buddy watch you to ensure you maintain an air source. I would also advise you to not practice this if you have mandatory deco and you don’t have a buddy. It would suck to blow off deco because you find yourself without an air source. When you are short on air, one second is forever!

The last reason I outlined, lack of practice, is just that. We all have to do three minute safety stops, it is a perfect time to practice pain in the ass skills we need to survive. For weeks I practiced my reverse frog kick and my lay throwing skills on my safety stop. Prior to that, I practiced my valve drills and buoyancy control on every safety stop I could. There is no excuse for not practicing; you have time built into every dive for it. Use the time; practice a skill that might save your life.

I can tell you from first hand experience, you may need to shut a valve down while entangled in zero visibility. It could be fishing net, monofilament, cave line or the long tail of someone’s snot that grabs a hold of you. You want to be prepared so you can maintain a calm cool collected manner. I promise, when the trouble comes, it is never alone.

3 comments

1 Anna { 05.26.08 at 1:08 pm }

Thanks Hans:) I just cant reach my valves. Trouble is I’m diving in 100’s with a steel backplate that already rests on the tank boots, so I cant move the tanks any higher. Good news though, I have someone willing to swap their aluminum 80’s for my single steel 100’d for Mexico (actually a very good deal for him as my steel 100’s are almost new). This guys tanks were new last year and I’m going to take the boots off them and put the bands much lower to solve my problems. What valves do you have on your tanks?

2 Hans { 05.26.08 at 1:26 pm }

Anna, I am sorry to hear you can’t reach your tank valves. You might consider removing the boots. Allie had to remove the boots to make her double steel 85’s work for her. The other option is to use a grinder and grind the boots down so you can move the backplate down. You really need to find a solution to the valve problem, what is the point of diving a system with redundancy if you can’t manage it?

I am using Dive Rite Manifolds and Valves on my double 80’s and side-mount tanks. Protech ordered the valves for me.

I have to warn you, do not expect ANYTHING to be in stock here in Mexico. Also, you need to expect to wait 1-2 months for anything to arrive if you order it and there is a greater then 50% chance it will not be in the order that is shipped.

I highly recommend you get your bands and manifolds while in the states.

For bands, I am using Highland bands. They are VERY VERY nice. I was supposed to get my bands from Protech, however they didn’t show up in the order and have never shown up. I was forced to go to the Tusa store here in town and pay a premium. There was the option to have the bands made by a local metal shop, however I skipped that one. I was too new in town to try and get that done

Lastly, that is a pretty unfair trade you are making! I would recommend you ask for enough cash to buy yourself your a manifold.

I paid $130/tank for seven used tanks here and I have a friend that just paid $40/tank for two tanks. The hydros are from 2006, but who cares. If I am still here in 2011, the tanks will have lived an excellent life.

By the way, did you finish your class with Charlie? How did it go?

3 Anna { 05.26.08 at 5:28 pm }

Going up to the St Lawrence this Friday and looking forward to it. I love diving with Jose and Fernando and actually just hanging out with a bunch of guys and wearing no makeup all weekend – low key. Plus I hear the current is wild in the St. Lawrence. I’m using Jeff’s 120s and I think that might just give me the extra reach I need to get to my valves. The problem about taking the boots off my tanks is people don’t like them on the boats like that. Other than teaching and the course this weekend coming I’ll probably not be doing too many dives this summer in doubles so I think I’ll just work on getting the 80s set up right. I’m going to take a look at those dive right valves. Might order them now while I still get cost. Looks like I will be working with Lehigh Valley this summer – so will get enough money to buy a canister light hopefully. They actually seem like a group of cool guys. Very laid back. They are trying to get a big mirror set up on one of the platforms int he quarry so their students can see what they look like when they dive. I sat through a few NAUI AOW dive briefings and the guy is very thorough. I like the way they teach, plus he’s going to put me on the shop’s insurance so I don’t have to buy my own. Off for Sushi with Jeff tonight. Will let you know how Canada goes:)