At what point do you run a line?

[Rick Murchison]

Still...you're completely right and if you'd immediately given the DIR answer of:
No direct ascent - always run a line.

I agree with that... however...

If it's a swimthrough (as defined in my previous post) it doesn't constitute an overhead, because you can swim directly to the surface, albeit with one turn at the exit of the swimthrough.

Now my question... would a DIR "direct ascent" really mean "straight line ascent" or would my "direct ascent" (you can always see the open water and make an unobstructed swim to the surface - and what I didn't say but is also included is a total distance of 130' or less) definition above qualify?
Rick

 

[Doc Intrepid]

Technically, there is steadfast answer for this question too. No direct ascent - always run a line. But, this is one of the very few cases where some deviation for real world practicality is almost universally practiced for "recreational" level dives.

The real problem behind divers failing to take safety precautions that are considered onerous or burdensome on "easy dives" - including some recreational swim-throughs - is that the entire attitude is founded on a series of assumptions. They assume first that nothing will occur out of the ordinary. No sudden medical emergencies, or blackouts. They assume next that this dive will proceed just as many have before, uneventful, no wrong turns, etc. They assume third that regardless of whatever circumstances they are faced with, they have adequate experience and resources available to them to deal with it. And based on these three assumptions (and perhaps a few more) they vastly underestimate the total universe of things that can go wrong in an overhead environment.

Then you wind up with situations like this one, posted by Azza in early August of this year (but there are hundreds of similar threads posted to SB over the past 5 years):
http://www.scubaboard.com/forums/showthread.php?t=197383

Two experienced divers, an artificial reef wreck deliberately sunk as an attraction - with huge holes cut into its hull and its hatches welded open - obviously the entire wreck is honeycombed with easy swim-throughs...

But they died. Took a wrong turn, disturbed sediment and silted out the area, and found themselves on a braille-dive which was simply inconsistent with their pre-dive assumptions, and from which recovery proved impossible.

It is these pre-dive assumptions and a tendency to underestimate what can go wrong that gets divers in trouble. Most of the time nothing in fact goes wrong, and they experience enjoyable dives. Which leads to even greater complacency. And then on one "easy" overhead swimthrough, something happens.

This is why I liked what RTodd had to say:

Technically, there is steadfast answer for this question too. No direct ascent - always run a line. But, this is one of the very few cases where some deviation for real world practicality is almost universally practiced for "recreational" level dives.

The rule on when to use a line isn't "grey". If you are penetrating an overhead, even a cavern with a broad opening on "three sides", run a line. You don't know what you don't know, including whether the geology includes clay, or fine sediment that could be stirred up by your presence or bubbles, etc. Consider it 'practice'. If you don't run a line, fine - thats your choice. But you make that choice based on assumptions regarding how the dive will proceed. On any given dive those assumptions could be mistaken. What if I'm your buddy and I have a heart attack? (dont leave me in there or I'll haunt you forever! )

Any diver adjusts the risk level they're willing to tolerate for each dive accordingly, along a continuum that runs from "convenience" to "dogmatic adherence to rules".

IMHO. FWIW...

 

[Meng_Tze]

This thread is getting convoluted to the extend that the original question now seems second focus.

Do you need to run a line to go into an overhead env.? No you do not. But you may need it to get out of that env.. And this is the issue here. If you go into an overhead environment, you need to assess what the risks and likelihood of these risks taking effect are.

If the system silts up and/or all lights are off......can I see the exit and get out?

Are there entanglement hazards, do I need to go through small openings to get out, do I have enough gas, will I not panic etc, etc, etc.

If at any time you feel that you MAY have to reference a line, you need to put one in. If you are not sure, you need to put one in, if you think "that will never happen, not happen on this dive", you need to stop diving

Another reference point would be: "how lonely will it be if I am stuck in this environment trying to find my way out?'

An overhead environment as accepted by the diving industry is where: you have a ceiling above which you can not go. This can be a virtual ceiling or a hard ceiling. In the case of a wreck, cave, swim through, most often/probably this is a hard ceiling. (you can do deco in these as well obviously).

Now to the DIR specific components.
AFAIK, Only Cave/T3 certified divers have business going into physical overhead environments if they stick to their certification limits. I know many otherwise DIR trained divers venture there, but they can at that time not claim to be DIR, not even when joined by cave certified divers. The 'team' (members) is at risk, there is no appropriate training and experience level according to the training limits and that goes against DIR philosophy.

Think of a scenario where total vis is lost, buddy is lost..... can the team make a safe exit? Do all members know how to manage these situations as a team/ their own (to take over from team members lost)?
This has nothing to do with comfort level, 'I know what I am doing', but plainly about risk assessment and management thereof.

 

[Rick Murchison]

- obviously the entire wreck is honeycombed with easy swim-throughs...

Somehow "honeycombed" and "swim-throughs" don't go together very well for me
To reiterate, to me a swimthrough must meet all the following criteria:
--
1) The entry and exit are two different points (may be the same hole if it's big enough that I never have to turn my back on the exit part of it).
2) I can see the exit to open water from the entrance and for the entire time I'm "swimming through."
3) I can see the entire passage is big enough to swim through without any entanglement hazard.
4) The total distance from entry to surface is 130' or less.
--
If it does, I don't consider that an overhead, so I don't consider it as needing a line. The question isn't "do I need to run a line in an overhead?" (yes!) but rather "what constitutes an overhead." I personally don't consider a swimthrough that meets all the criteria above to be one, but the ultimate arbiters of "official DIR" at GUE may not agree. The question is, if they don't, then how do they define an overhead? An I-beam? Two I-beams? A piece of deck plating that's 6' wide? 10'? 50'? When does it stop being something you can swim under and become an "overhead?" I'm satisfied that if it fails any of the four tests I've listed then it is an overhead and a line is required. If there's another "official DIR" definition I don't know about, what is that? Bear in mind that any obstruction overhead - even a single I-beam - can add a horizontal component to the "direct ascent to the surface"... so if that's a problem, how much of a horizontal component to the direct ascent disqualifies it as a direct ascent?
Rick

 

[RTodd]

The real problem behind divers failing to take safety precautions that are considered onerous or burdensome on "easy dives" - including some recreational swim-throughs - is that the entire attitude is founded on a series of assumptions.

You are absolutely correct. This is why I try to stay away from ever agreeing with the, well in this situation, what about violating a DIR principle questions. I made that mistake here. It is a slippery slope and made much worse when the diver does not have a pretty broad range of experience to judge the risk of whether or not deviation X is acceptable. This is compouned by those without the proper knowledge base who have gotten away with an unnecessarily risky situation numerous times with no adverse consequences so they assume the practice is fine.

The problem is that almost no diving situation is that risky on a one off basis. So, those that don't embrace the philosphy see it as somehow violating their freedom to choose something. Where accidents happen is when several things don't go your way on a dive. DIR is designed give you the tools to stop the chain of events that tend to cause accidents by preventing as many problem areas as possible and making the reactions to unavoidable potential problems run smoother and thus not result in further problems. The bashers just see the pieces and call it dogmatic without ever understanding the whole system.

 

[Kim]

The problem is that almost no diving situation is that risky on a one off basis.

To be frank I think exactly the opposite is true - and THAT is what GUE is trying to address from what I can see. The fact that someone can perform any given action (like crossing a road for instance) thousands of times with absolutely no penalty doesn't negate the fact that every time they do it they are running a risk, and in MANY cases a lethal one. (true for road accidents, true for diving) It doesn't really matter what the odds are, a gamble is still a gamble - and I wasn't aware that gambling was something GUE supported, especially when a few precautions can remove/reduce/nullify the risk.

Still - that aside, and back to the original question. I think Rick nailed it:

What is GUE's definition of an overhead?

I'm fairly sure that once that is clear the answer to the OP's question will also be.

 

[Doc Intrepid]

Somehow "honeycombed" and "swim-throughs" don't go together very well for me
To reiterate, to me a swimthrough must meet all the following criteria:
--
1) The entry and exit are two different points (may be the same hole if it's big enough that I never have to turn my back on the exit part of it).
2) I can see the exit to open water from the entrance and for the entire time I'm "swimming through."
3) I can see the entire passage is big enough to swim through without any entanglement hazard.
4) The total distance from entry to surface is 130' or less.
--
If it does, I don't consider that an overhead, so I don't consider it as needing a line. The question isn't "do I need to run a line in an overhead?" (yes!) but rather "what constitutes an overhead." I personally don't consider a swimthrough that meets all the criteria above to be one, but the ultimate arbiters of "official DIR" at GUE may not agree. The question is, if they don't, then how do they define an overhead? An I-beam? Two I-beams? A piece of deck plating that's 6' wide? 10'? 50'? When does it stop being something you can swim under and become an "overhead?" I'm satisfied that if it fails any of the four tests I've listed then it is an overhead and a line is required. If there's another "official DIR" definition I don't know about, what is that?
Rick

I don't think we disagree Rick, and I was not replying to your previous post (you posted while I was typing!)

There is a fallacy that within "doing it right" there are strictly proscribed constraints on behavior and equipment, etc. This is certainly true to some extent, but whereas JJ was more specific with respect to issues like smoking or health practices, there were and still are many areas where choices should be made by informed, analytical divers. I'd argue that as the concept has matured over the past 15 years, the opportunities for choices made by divers who are well-instructed in the overall concepts have increased as the focus has moved beyond its cave diving origins and have been applied increasingly to the open water recreational environment. There is room for calculated ambiguity where guys may make different decisions: "5' or 7' hose?" "running the hose beneath a can light or a pouch?" on caribbean wetsuit rec dives where an 18 watt HID might be unnecessary? And how many otherwise DIR oriented divers might use a computer on a two-week liveaboard to more precisely track residual nitrogen levels over 4-5 multilevel rec dives a day for 10 days in a row?

Not every question has only one answer.

To respond to your post, Rick, I dove on Guam for a couple years and other south pacific islands during that time. There were plenty of holes in the coral walls that were between 3' and 12' long or more, where you could swim from one side to the other. I swam through them, and I didn't run a reel I'd likely do it again.

One I-beam or a six foot deck plate? While Cavern and Cave I define "overhead" pretty well, within a cave diving context, I don't know of anything George wrote or any other DIR text drawing a line in the sand defining the point at which a recreational swim-through becomes an 'overhead environment'. Its nearly always going to be a circumstantial call by the divers doing the dive. That said, its likely always best to err on the side of caution.

FWIW. YMMV.

 

[Rick Murchison]

FWIW. YMMV.

Got it!
Agreed!
Rick

 

[lamont]

However...
w/r/t DIR, there seems to be a camp emerging that has an idea that "everything that's not approved is prohibited" ...

...compsed mostly of post-DIRF students on the internet.

 

[lamont]

so, i've been in a hard overhead environment at about 30 fsw on a reef down in akumal where the 'swimthrough' was probably 30 feet from end-to-end. i felt comfortable down there without a line since i had doubles, a backup mask, DIR trained buddies, about 3h of gas on my back, etc, and the bottom was rock/coral that wouldn't silt out. the biggest hazard to me down there was the other recreational single-tank divers entering the overhead where their skills, gas, etc were unknown -- not the lack of a guideline...