DIR Details

[Deep Blue]

Everyone,

I have posted below Puddlejumper's response to my email originally posted under Deco Procedures so we can start some discussion on DIR specifics.

Specifically addressing the issue of a balanced rig, this goes to the heart of the DIR concept as I understand it. You need to dive the appropriate equipment for the environment. For example, if you correctly balance your equipment, ie. do not dive steel tanks with a wetsuit, or aluminum tanks with a drysuit, you have no need for double wings, or wings that are overly large and trap air.

As much as possible, you should be able to swim your gear to the surface even with a failure of your BC. If you are diving aluminum doubles, and you dump any stages, a weight belt and possibly your light, you should be able to at least get to the point where your suit is bouyant enough to get you to the surface.

If you are diving dry, ditchable weight is not as much an issue, since you already have backup bouyancy control via your drysuit. However, a steel plate may not be the best choice if you already don't have any releasable weight, since it makes you unnecessarily negative. Personally, I dive an aluminum plate with my steel tanks for this very reason.

The more air you need to put into your BC, the less efficient you will be in the water, and the poorer your trim will be.

Again, in my opinion, there is no need for any BC on a single tank more than 45 pounds and most people should not need more than 30 pounds if they are properly weighted, (which most open water divers are not). If you are diving doubles, a 55 pound BC designed for double tanks is more than sufficient.

While I am on the topic, just as a ferrari is a butt kicking vehicle on the autobahn, but may not be the best choice for driving the Rubicon trail, BCs wings are similarly suited for different configurations. I have never seen a double tank BC, ie the DiveRite classic wings or (shudder) the OMS bungee wings used efficiently on a single tank. Will they get you out of the water alive? Most likely but will they do it efficiently? no. A much better choice is a wing designed for a single tank, ie a DiveRite Venture wing or a Halcyon Pioneer wing. If you dive doubles, choose a wing designed for doubles. That is the beauty of the backplate system, you can easily change aircells based on your needs, one backplate, 2 aircells. If you are getting into diving seriously enough that you will be diving doubles, you really need to fork out the extra 300 dollars for a proper wing.

The same goes for the double redundant wing. Will it kill you? Probably not, but it is unnecessary complication which adds failure points to your rig. Extra hoses, extra inflator, etc etc. Dive a properly balanced rig and you avoid the complications. I have seen the extra inflator take off on a diver who then made an uncontrolled ascent. Ok, don't keep it hooked up, but then if you don't test it every dive, how can you be sure that it will work when you need it? and why do you keep an extra hose on your first stage to complicate your hose routing?

Properly configured divers will have a lift bag on any serious dive of at least 50 # anyway, if you do damage your BC and your drysuit at the same time, use your lift bag as a third backup source of bouyancy. I have done it in training and it works!!! Now you are using a piece of equipment that you already need and are not taking extra stuff into the water. Dive DIR-avoid the christmas tree look.



>Posted by: Puddlejumper yesterday:

I breathe and donate the long hose.

Yep I dive a back plate (both soft pack and back plate depending on the need) and wings (though I have a dual wing ).

Personal Fitness. No disagreements here.

Team diving philosophy. Seems about right. Though a good team should IMHO work this out over many dives before diving something serious.

Properly balanced rigs? Standardized Equipment Cinfigurations? Starting to get there. What constitutes a properly balanced rig? IMHO this should be based on an individual divers requirments. Also the diving conditions have a large impact on this as well. This ties into a standardized rig as well. Example in point I dive a set of doubles on a OMS stainless back plate. I use a dive rite dual rec wing with 51# lift. I am diving a Apexs 200 right post (long hose with a stainless clip attatched -cave line). My dry suit inflation comes from my right post. My SPG is on my left post and has a cover as well as a retractor. My cannister light is attatched to my back plate right side. And my drusuit gas (when I will need it ) will be attatched to my left with the dreaded metal on metal connection that I also use for my light. This is not a DIR rig as my understanding goes. But what will make me a "cluster" or unsafe diver here.


>Posted by: Deep Blue Posted on: Yesterday at 05:26:08pm
How can the fact that DIR is an outgrowth of the Hogarthian configuration be a reason not to ascribe to its principals? Also, the commonly held perception of a stroke is an unsafe diver. I am very selective of who I do any serious diving with, I won't do those dives with unsafe divers. I would love to really understand your true issues with the system on a logical basis. What do you not like about the system itself?

Breathing and donating the long hose?

Backplate and wings configuration?

Properly balanced rigs?

Standardized equipment configurations?

Personal fitness?

Team diving philosophy?

I am not trying to throw bombs here, I genuinely would like to have a dialog on the merits of the system, not the noise that tends to surround it.

If there is enough interest, I know that both Jon and I would be happy to have a discussion in the advanced diving forum.