Preparations for first Tec course

[divezonescuba]

I am trying to get some experience with my gear prior to enrolling in my first Tec course. I am gearing up using the same type of tank setup that I will be required for the course. This a back mounted set of al80s. Side mount and steels are not an option for the course.

So far a few issues have come up which I would appreciate some friendly advise on before I start the course in December.

My gear which I am using consists of a plastic Diverite plate and dual bladder Diverite rec xt. The harness and bands are Dolphin Tech. I am using 3mm wetsuit. As I will have to use in the class, I am using a set of al80s with a manifold.

First, I found out that the band bolts which are 4.75 inches were too short. It was necessary to go to six inch threaded rod with nylock nuts. The ends of the rods are not in danger of puncturing any exposure suit that I might be wearing. Are there any other potential issues with using the longer threaded rod?

Second, I found out that there was no way that I could reach the valves with the top band at the crown. Due to some injuries in my younger days, I cannot engage in any exotic shoulder maneuvers. By moving the band down a few inches, I found that could reach the valves under water. In the water, without any weight, the movement of the bands down allowed me to have good trim, at least in a 3mm. I am naturally feet heavy so moving the bands down appeared to coincidentally help address that problem. So, if I have good trim and can reach the valves, is there any reason why I would want to try to move the bands back up toward the crown and possibly cause me to lose trim?

I am really glad that I have started doing this in advance so I have had a chance to debug the setup.

Thanks.

 

[DevonDiver]

First, I found out that the band bolts which are 4.75 inches were too short. It was necessary to go to six inch threaded rod with nylock nuts. The ends of the rods are not in danger of puncturing any exposure suit that I might be wearing. Are there any other potential issues with using the longer threaded rod?

Size the rod correctly in the direction of your back. Extend the surplus length rearwards, away from you.

I'd suggest not cutting it down, as you might consider changing to a different (metal) backplate later on.

Second, I found out that there was no way that I could reach the valves with the top band at the crown. Due to some injuries in my younger days, I cannot engage in any exotic shoulder maneuvers. By moving the band down a few inches, I found that could reach the valves under water. In the water, without any weight, the movement of the bands down allowed me to have good trim, at least in a 3mm. I am naturally feet heavy so moving the bands down appeared to coincidentally help address that problem. So, if I have good trim and can reach the valves, is there any reason why I would want to try to move the bands back up toward the crown and possibly cause me to lose trim?

If you can maintain proper trim, then the bands are well located. Many divers initially struggle with valve shut-downs. For a small few, it's due to significant shoulder immobility. For most, it's due to bad technique. A credible tech instructor can get 99% of their divers to achieve timely shut-downs.

Common errors are:

• Reaching around, not directly up and over (forearm brushes the ear).
• Dipping the chin to the chest / not arching the neck backwards
• Not staying horizontal/dropping the legs

 

[KevinNM]

I'm still not good enough at this to get into a GUE tech class, but I ve got some similar experiences.

I screwed up my left shoulder in a skiing accident 15 years ago, I put the humerus through the scapula. So when I took a doubles course with a very patient instructor I simply could not reach the left valve. At most, in a bathing suit, I could touch it. I failed that course.

So I worked on it and now I can do a valve drill. The left side is signficantly harder to do (particularly reopening the valve) but it is doable under control in a reasonable time.

So before going to equipment solutions I'd suggest working on stretching and range of motion. Figure out what motion you need and try to get there. Bands and light weights. You can also, by propping up the tanks on something strong, just work on in the house. Stand up next to the vertical tanks. Crouch a bit, pull on the BP straps, then move until you can grasp the valve, then slowly stand up until the tank is beginning to tighten the straps on you BP or until it starts getting painful, then you want to stop and hold that stretch. Then work on opening and closing the valves once you can hold the valves without being in pain. The best PT I had told me it shouldn't hurt, but uncomfortable was ok.

This may not work. It's possible that backmount won't work for you too. Anyhow I'd talk to the instructor and be sure they won't freak out if you show up with that setup. Send them a picture of the tanks and explain the issue.

Trim is the main reason I told to not move around the bands. Most people go head heavy when you do that. The second is that when you rent or borrow tanks you can expect them to be set up with the bands at the crown, and they expect them back that way too.

And be very damn careful trying to learn a valve drill by yourself under water, particularly if you have issues opening valves. It is all too easy, when you are learning the steps, to close both posts at the same time.

 

[divezonescuba]

Thanks for the responses.

 

[toby43]

I am trying to get some experience with my gear prior to enrolling in my first Tec course. I am gearing up using the same type of tank setup that I will be required for the course. This a back mounted set of al80s. Side mount and steels are not an option for the course.

So far a few issues have come up which I would appreciate some friendly advise on before I start the course in December.

My gear which I am using consists of a plastic Diverite plate and dual bladder Diverite rec xt. The harness and bands are Dolphin Tech. I am using 3mm wetsuit. As I will have to use in the class, I am using a set of al80s with a manifold.

First, I found out that the band bolts which are 4.75 inches were too short. It was necessary to go to six inch threaded rod with nylock nuts. The ends of the rods are not in danger of puncturing any exposure suit that I might be wearing. Are there any other potential issues with using the longer threaded rod?

Second, I found out that there was no way that I could reach the valves with the top band at the crown. Due to some injuries in my younger days, I cannot engage in any exotic shoulder maneuvers. By moving the band down a few inches, I found that could reach the valves under water. In the water, without any weight, the movement of the bands down allowed me to have good trim, at least in a 3mm. I am naturally feet heavy so moving the bands down appeared to coincidentally help address that problem. So, if I have good trim and can reach the valves, is there any reason why I would want to try to move the bands back up toward the crown and possibly cause me to lose trim?

I am really glad that I have started doing this in advance so I have had a chance to debug the setup.

Thanks.

You will get some good advice here but honestly dont worry too much, choose a reputable instructor and they will help you sort it out.

 

[rjack321]

Second, I found out that there was no way that I could reach the valves with the top band at the crown. Due to some injuries in my younger days, I cannot engage in any exotic shoulder maneuvers. By moving the band down a few inches, I found that could reach the valves under water. In the water, without any weight, the movement of the bands down allowed me to have good trim, at least in a 3mm. I am naturally feet heavy so moving the bands down appeared to coincidentally help address that problem. So, if I have good trim and can reach the valves, is there any reason why I would want to try to move the bands back up toward the crown and possibly cause me to lose trim?

How far down did you move them? Most peoples' head runs into the isolator if you move the bands down. Actually most peoples' heads hit the isolator even with the bands at the crown. Getting your head back is key to having a decent arch in your back which keeps your knees from dropping. Any video or pics of you in the tanks?

If possible you might want to have an extra day with your instructor a month or two before the start of your actual class. Work on the doubles setup with him or her then you know you're on a decent path while you get more comfortable over a few months of recreational trial dives.

 

[guruboy]

I would suggest getting to a point where you can maintain trim and buoyancy very well while doing drills first. Tec classes are expensive to retake.

Maybe a GUE doubles primer or Fundamnetals course, or similar?

 

[beester]

I would keep the bands where they were (at the top band just below the crown) and first check other methods. Reasoning being that you are personalising your gear to solve a problem that might well be solved in other ways. If after the course you go tech diving and use other tanks which are not setup like this you'll need to always adjust them. A major pain.

Like andy and Kevin already said. The truth is that most people even with past shoulder injuries (I had a broken scapula from a motorbike accident) will be able to reach the valves by using proper technique (trim, head back, arm over shoulder not turned away from shoulder) and some stretching. The only gear thing that could matter is the size of your garments (drysuit/undersuit) but since you are diving tropical in a 3mm I'm assuming there is more than enough stretch in the 3mm neoprene to accommodate this.

What I would check with feed heavy is the weight of your fins. Many tech divers will use heavy fins (scubapro jetfin like), which work very well with floating feet (typically an issue when you dive drysuits), but are much to heavy when diving a thin neoprene suit.

Good luck.

 

[rhwestfall]

Are you sure you have your harness set properly, and have your plate in the proper location too? Your instructor (or an experienced mentor) is key in this. Careful doing things "on your own" as you may be developing "bad habits" that you then have to un-learn....

 

[RyanT]

I am naturally feet heavy so moving the bands down appeared to coincidentally help address that problem. So, if I have good trim and can reach the valves, is there any reason why I would want to try to move the bands back up toward the crown and possibly cause me to lose trim?

As others have said, it may very well be an issue of reconfiguring your other gear (e.g. harness & plate). But...there is nothing magic about the bands at the top of the crown. I had a set of HP 100s and I did exactly as you did. I found that once the bands were moved down a couple of inches, I could better reach my valves and my trim was good. My head did bump the isolator valve, but only when I tilted my head back really far. So bumping my head was a non issue and everything else worked. Do what works for you. In your course your instructor will (should) help you configure your gear. So if you end up moving things around thats fine too. But for now, start with what works for you.