Thursday 30 November 2006

Anatomy of the GUE Valve Drill

This article outlines the process and reasoning behind the DIR valve drill, as understood by myself. firstly, a caveat. This is my interpretation of the valve drill, and my thought process behind it. If you want to learn how to do it officially, then you need to take a GUE course, or speak to a GUE instructor.

Process summary

The basic valve drill involves closing and opening all three posts on a twin set starting with the right post, then the isolator, then the left post.

Process Details

1. Signal to your team you are going to perform a valve drill
2. Wait until your team is in place and then continue
3. Purge Backup regulator
4. Shut down the right hand post whilst simultaneously signalling you are manipulating a valve to your team
5. when the post is shut down, breathe down the regulator until it "locks".
6. Remove the regulator and replace with your backup regulator
7. clip off your primary regulator on the right chest D ring
8. Open the Right post
9. Unclip the primary regulator and purge it
10. Remove the backup regulator from your mouth and replace with the primary regulator
11. Shut down the Isolator whilst simultaneously signalling you are manipulating a valve to your team
12. When the Valve is closed, Re-open the isolator
13. Move your torch to your right hand
14. Shut down the left hand post whilst simultaneously signalling you are manipulating a valve to your team
15. When the post is closed, purge the backup regulator until it "locks"
16. Open the left post
17. Move the torch to your left hand.
18. Check the position of your right hand post
19. Check the position of your isolator
20. Move the torch to your right hand and check the position of your left post
21. Signal that your drill is complete

Looks like a lot of steps, but it really should not take you any more than a minute or so to go through the drill in a nice slow fashion, and I've seen people do it a great deal quicker than this. The trick is to go through the drill slowly and carefully again and again until the movements become muscle memory rather than conscious action. At that point, you can begin to speed up the drill until it becomes both smooth and fast.

Anatomy of the process

Now that we understand the steps we have to take in order to complete the drill, let's look at each step in a little more detail and explain some of the reasoning behind it.

1. Signal to your team you are going to perform a valve drill

OK, so we are diving in a two or a three. We signal to the rest of the team that we are going to do a drill. This means a clear point at all the other team members indicating "You!" and "You", then pointing at your mask indicating "watch me", and then a turning motion with both hands indicating valve drill, hence "You! Watch Me!" "Do a Valve Drill!". this is critical as the rest of the team need to know what is going on so that they are ready if there is a problem. A problem could be you shutting down both posts and leaving yourself out of gas, or something going wrong with your kit. In either situation they need to be ready to step in, and critically, they need to be doing nothing else but watch so that they are not doing any other drills at this time.

2. Wait until your team is in place and then continue

If you are swimming in a line, you need to give your team time to get into a triangle formation all pointing inwards so that they can see you, and see your valves. This is important so that they are in the correct position to donate a long hose if they need to, and so that they can follow your movements on your valves. so have patience and let them get ready before you get going. Once you are all in position, you maintain eye contact with your team. This is done to ensure that firstly, you are keeping your head up during the drill and not getting absorbed in what you are doing, to keep your head up so that you maintain trim, and also so that you maintain situation awareness in case another member of the team has a problem themselves. you are only doing a drill, and need to keep an eye on your team at all times, including when you are doing drills.

4. Shut down the right hand post whilst simultaneously signalling you are manipulating a valve to your team

The signal for manipulating a valve is a clear "Attention!" signal, which consists of a controlled side to side motion with your torch beam. this must be a controlled and relatively slow motion, very different from a "I need assistance URGENT" signal which is a very quick motion with the torch. The signal is continued until the valve is closed. The signal should be given so that all other team mates can see it, and if you are diving in a team of three it is important that you do not get caught in the trap of only signalling to one person.

5. When the post is shut down, breathe down the regulator until it "locks".

This one creates a little discussion, but there are a couple of reasons why we breathe down the regulator. Firstly, it is a check that we have shut down the correct post and indeed are breathing the correct regulator. Most important, it depressurises the regulator. If A post or hose has a small leak, then turning off the post might leave the hose bubbling for some time. The hose needs to be depressurised in order to stop the bubbles. If the bubbles stop after you depressurise the hose, you have found the leak. It will also allow a team member, in a real situation, to reseat the first stage if necessary. finally, it is continual training against panic when you suck on a regulator and nothing happens. It becomes instinctive after several hundred drills - regulator locks, take it out and replace with a backup. this seems obvious, but what you are removing is the initial "Oh shit!" when the regulator locks.

6. Remove the regulator and replace with your backup regulator

The critical word here is "Remove". we do not spit out the regulator and replace it. We remove it with our hand and KEEP it in our hand until we are breathing successfully from another reg. This is so that we do not have to suddenly search for it if the regulator we wish to breathe off fails. It also means we do not have a regulator dangling around. there is a principle in DIR that a regulator is either in our hand, in our mouth, or clipped off. We never leave a regulator hanging as then we do not know exactly where it is. so, in this step, we remove our regulator with our right and then, whilst holding on to that regulator, we place the backup regulator in our mouths.

7. Clip off your primary regulator on the right chest D ring

In the last step, we were left in the position of breathing off our left post, and holding the primary regulator in our right hand. Now, we clip off the regulator onto our right chest D ring. This keeps it neatly stowed away whilst we continue our drills and continues with the ethos that we always know where the regulator is. we clip it to the right chest R ring as opposed to the left because we have a policy of not clipping anything across the body. this again is muscle memory. We do not get into habits of clipping across the body because sooner or later we would clip something across the `long hose and trap it.

8. Open the Right post

So, with the primary clipped off and breathing off the backup, we now reach back and open up the right post, remembering to keep our eyes at all times on our team. We open the post until it is fully open.

9. Unclip the primary regulator and purge it

We now unclip the primary regulator from the right chest D ring and give it a purge. This is to ensure we have turned on the correct regulator and that we are going to get gas from it when we attempt a breathe, which we are shortly to do. Note that we keep hold of the regulator during the purge process and continue to keep hold of it to the next step.

10. Remove the backup regulator from your mouth and replace with the primary regulator

As with the earlier step, we remove the backup rather than spitting it out. We now have the backup regulator in our left hand, and the primary regulator in our right hand, so we replace the primary regulator in our mouth and begin to breathe from it. We can now let go of the backup regulator.

11. Shut down the Isolator whilst simultaneously signalling you are manipulating a valve to your team

We now close down the isolator valve, and as with the earlier steps, we continue to keep our eyes on our team, and clearly signal with the torch in our left hand. We continue to close down the valve until it is fully closed.

12. When the Valve is closed, Re-open the isolator

We do not have a regulator to breathe down with the isolator, so once we have fully closed it, we fully re-open it again. Simple.

13. Move your torch to your right hand

Having finished with the right post and isolator, the next post we are going to deal with is the left post. However, we have an issue here because we hold the torch in a Goodman handle in our left hand. Now this is where some smartarse will say “ahh but I can still manipulate the valve with my left hand”, but what that person would also do is send erratic light signals all over the place as they do so, which could easily be misinterpreted as a problem. So, we don’t do that. What we do is switch the torch to our right hand by sliding it out of the Goodman handle, and grasping the torch in our right hand by the barrel of the light head. This means we can hold the torch and continue to give signals with it, and frees up our left hand to manipulate the left post.

14. Shut down the left hand post whilst simultaneously signalling you are manipulating a valve to your team

Remembering to keep our eyes on our team, and continually giving a clear side to side attention signal, we now reach back with our left hand and shut down the left post until it is fully closed.

15. When the post is closed, purge the backup regulator until it "locks"

Now that the post is closed, we reach to our backup regulator with our left hand, and purge it until it empties. This will depressurise the hose for exactly the reasons we described earlier. Once the regulator has stopped bubbling, we know we have shut down the correct post.

16. Open the left post

We can now open the left hand post. We open the valve fully, and then give the backup regulator a purge to ensure it is functioning correctly again.

17. Move the torch to your left hand

We now slide our left hand back into the Goodman handle of the torch.

18-20 – The flow check

We have essentially finished the valve drill now, but we need to just do a flow check to ensure all posts are back in their correct positions. This is a general DIR policy. Whenever anyone, including yourself, has been manipulating the valves, we do a flow check at the end to ensure all the valves are where they are supposed to be. In the case of the valve drill, all posts should be back in the open position. So we reach back with our right hand and check that the right hand post and the isolator is open. We take the torch in our right hand and check the left hand post is open, and then finally place our left hand back in the Goodman handle and we have completed the flow check.

21. Signal that your drill is complete

As the drill is now complete, we give a signal to the rest of the team that we have completed it and are ready to move on to the next person’s drill, or continue with the dive. There are different ways we do this, but the way our team does this is to give a circle with the torch indicating “OK”. The other team members return the signal. This gives the other team members the information that you are happy, but also you are getting a confirmation from them that they are satisfied that you have put all of your valves back where they are supposed to be. If you had made a mistake and left a post closed at any point, they could intercept you at this point and rectify the situation for you.

And that is my anatomy of the GUE valve drill.