The "other" end of the DIR question

[Paul Evans]

Oh well. I knew when I wrote it that I was inviting this question, so here goes.

Let me start this off by admitting that I don't expect to convince anyone off of their practice. For every negative I suggest, there is a positive that can be countered. After weighing the benefits and the risks, and doing more than my fair share of dives both ways, I have opted not to use a line in most situations. That said, I will support my opinion.

In my opinion, a line in a wreck is a greater liability than safety tool. For one, it is an entanglement hazard. Especially in the areas where you might be most tempted to use it, such as areas of poor visibility and directional changes where there are more than one choice, entanglement is a real risk. If you navigate into tight quarters, this risk becomes even greater. Add a buddy, and the risk is doubled. Even if you are an expert with the line and avoid entanglement, it is very possible that someone else, who you are not even diving with, may become entangled in your line, and cut it to free themselves. I have seen this happen. I have followed cut lines as they dissapeared into the recesses of a wreck, and followed it back to some very wide eyed, lost divers, who were very happy to see me. I have rescued lost divers with birds nests of line wrapped all around them and led them out from their doom. Line becomes even more unmanageable when free, and there is no good way to deal with it. If you leave it slack where it lays to try and follow it out, it will bite you. If yopu reel it in, you can't follow it out.

Laying line in a wreck is not like laying line in a cave. Edges of most things are jagged and rusty and slices through line slicker than snot. In caves, flow, if there is any, is usually in one direction. You can wrap the line thus so it remains properly tensioned with the flow. In a wreck, surge moves water back and forth, sometimes violently. This back and forth motion frays line at every point of contact. Once severed, it becomes more of an entanglement hazard, as described above. In a wreck, every loop you make to secure the line is one additional possible point of fray. You need to weigh the need to secure the line with the need to minimize friction. They also do not always lay as you expect them to, sometimes they drift. They can get cought on something and be severed, or they can wind up in an area that when followed, lead the diver through a smaller part of the wreck that cannot be fit through. I have also seen this happen.

Caves are natural formations. They follow no predictable course or patterm. Wrecks are manmade structures. They are predictable, once you understand how they are built. You can use logic to navigate. There are often multiple points of possible exit, and light from the outside filters in to lead you to entry/exit points and to sometimes partially illuminate the way. Another important point to consider is that wreck penetrations are not typically measured in the thousands of feet, like a cave. In even the largest wrecks, you are rarely more than 50 feet from an exit. I challenge anyone to find a wreck penetration that puts you over 100 feet from an exit point.

The method I use to penetrate wrecks is a combination of progressive familiarization and visualization. In short, you repeatedly cover the same ground, progressing further each time as you become more familiar with the area. At the same time, you concentrate on visualizing physical structures to act as reference points to guide you back the way you came in the event of a total loss of visibility. Like using a line, this is a skill that requires practice, concentration, and skill. Trying to do both at once comprimises the effectiveness of both. Its task loading, which all technical divers know decreases performance. Trying to do an effective progressive penetration, AND visualization, AND laying a line for "Backup" means you are more likely to screw something up.

To run a line and not use it as a crutch is not as easy as it sounds. You wouldn't lay the line if you don't believe it can be used to guide you safely out. If its there, why not use it? To me, it inspires a false sense of security, and people can and do rely on the line to get them out. Cave divers especially use the line as a guide. In a cave, they rely on it. They don't "learn" every foot of the cave as they go in. To tell them to use it on a wreck but not to rely on it is a tall order.

Part of the responsibility every diver has is risk assumption. This means determining the risks, weighing them, devising the best plan for minimizing or eliminating them, and then again, evaluating the resulting methodology to make the choice as to if they will assume the responsibility of diving with that risk or not. In DIR, the methodology does the first parts. Outside of DIR, we do it for ourselves using the combined knowledge of what we have learned. Here, on this issue, risk exists both ways. If you choose to penetrate a wreck, you are taking a risk, regardless of how you choose to do it. I choose to take the risk without the line to eliminate that set of risks. In doing so, I am assuming the responsibility for the risk of not having a line. I have done over a thousand deep, long penetration dives into many wrecks, and this method works for me. When I teach wreck students, I teach them both ways, give them all the information on the risks present in both styles, and tell them how I do it and why. I make them practice and master both ways, and I make them do penetrations both ways. When they leave my course, they are capable of doing it both ways, and informed enough to decide how to proceed. Most important, they are aware of the risks involved in either way.

I'm not about to tell you or anyone else not to use a line in a wreck. That wasn't my goal in answering this request. What I did hope to accomplish, is to give you an understanding of some of the risks, so you can factor them in to your risk assesment.

Hey AAdiveRex.....Ever thought about writing a Book

Thats the sarky bit out of the way, now the serious bit


Ever thought about writing a Book

 

[jhelmuth]

would you consider knowing the wreck blind AND laying line?

seems to me if for some reason you have to exit in zero vis,
it would help to have that line even if you know the wreck
blind.

in other words, why would you oppose using the line not as
a crutch but as a safety item, a back-up to your memory
and mental clarity?

Maybe AARexDiver will chime in on this to confirm or clarify, but part of assesing the risk in a dive and addressing the approach to the dive is to exaimne the various ways the dive can be approached and constantly look at it until you can minimize the risks (all potential hazzards) to the point where you are comfortable with it - or NOT, and don't make the dive. Memory and mental clarity, as tools to execute a dive, are closely tied to the gas selection and dive plan. How good is your mental clarity at the depth intended and on the gas intended? Can you succesfully run a line in a werck and use it to get out? Probably. Will it create an entanglement hazzard? Maybe not. Is there evidence that supports the claim that a line can be and entanglement hazzard (or break and be useless as a tool to get out)? Absolutly!
To me, it seems very logical that one would use their knowledge of a wrecks predictable passages and structure, along with many "memorized" practice runs (successively going deeper into the wreck) that familiarize you with its entries and exits. That assuption is also based on a well selected gas mix that accounts for potential narcosis and oxtox, as well as termal factors (helium and "light" inert gases tend to make the body "colder" and can impair the divers ability to perform otherwise prediciable skills and tasks).
Again - never dive beyond your training. If DIR insists that running a line in a wreck is the "best" way to navigate the wreck, then I'd take issue with that and go so far as to say that they do not adequetly train their members (I do not know if that is a DIR requirement, so please do not take it as such. I'ts just an example).

AARexDiver makes some very compelling points about diving a configuration that is not ridgid for rigidity's sake - but to dive a configuration because it makes the most sense for the diver and the dive. I'd have to give AARexDiver more respect than any other memeber of this board just because he clearly understands the value of flexibility of configurations to best approach the dive requirements and that you alone are responsible for your dive (not your buddy).

 

[android]

I would much rather dive with AADiveRex than some of the narrow-minded DIR divers that post here on a regular basis. Being able to analyze and evaluate each situation is a far greater challenge that following ritual practices and procedures passed out by the powers that be. (That almost sounds like a religous argument, doesn't it?)

 

[O2BBubbleFree]

Hey AAdiveRex.....Ever thought about writing a Book

Thats the sarky bit out of the way, now the serious bit


Ever thought about writing a Book

Let us know if you do. In the mean time I predict you're going to get a long line of serious divers lining up to take your classes!

 

[Soggy]

I would much rather dive with AADiveRex than some of the narrow-minded DIR divers that post here on a regular basis. Being able to analyze and evaluate each situation is a far greater challenge that following ritual practices and procedures passed out by the powers that be. (That almost sounds like a religous argument, doesn't it?)

I can't believe I'm being sucked into this, but...

DIR is *all* about analysis of situations, gear, skills... Gear is the smallest portion of the DIR system...it's all about procedures, muscle memory, self-sufficiency, and personal and buddy skills. The people that *I* know that are DIR could care less what the "powers that be" say unless it is backed up with a well thought-out argument. DIR is a system, and throwing something into the config without thought about how it affects the system is dangerous.

 

[H2Andy]

Let me start this off by admitting that I don't expect to convince anyone off of their practice. For every negative I suggest, there is a positive that can be countered. After weighing the benefits and the risks, and doing more than my fair share of dives both ways, I have opted not to use a line in most situations. That said, I will support my opinion.

which is what i had asked you to do, thank you for taking
the time to do it.

not having dived any wrecks, i appreciate you outlining
the downsides of lines inside a wreck. the only two things
i had thought of myself were the danger of cutting the line
on sharp metal or getting entangled in the line in a narrow
passageway.

 

[H2Andy]

I would much rather dive with AADiveRex than some of the narrow-minded DIR divers that post here on a regular basis. Being able to analyze and evaluate each situation is a far greater challenge that following ritual practices and procedures passed out by the powers that be. (That almost sounds like a religous argument, doesn't it?)

i don't think calling anyone "narrow-minded" helps anything.

please, if you can't contribute without calling people names,
don't contribute at all.

 

[jonnythan]

Soggy's absolutely right. The very essence of DIR is analyzing everything to the smallest detail. Android unfortunately hears what all the non-DIR people say about DIR. Any DIR guy on this forum will be more than happy to explain every subtlety of the reasons why something is done and analyze situations for you.

 

[jonnythan]

I would much rather dive with AADiveRex than some of the narrow-minded DIR divers that post here on a regular basis.

Care to name one of these narrow-minded DIR divers? I've been here for quite a while and can't think of any DIR guys here I'd call narrow-minded.

 

[android]

i don't think calling anyone "narrow-minded" helps anything.

please, if you can't contribute without calling people names,
don't contribute at all.

I don't believe I called any specific person a name. The qualifier "some" allows the DIR reader to decide whether they are in the "narrow-minded" subset or not.