Swim throughs - what could possibly go wrong?

[Foxfish]

Much has been said and there are two extreme positions being taken by some people here that don't allow for any compromises. I don't know if the OP is trying to validate his actions or asking in general if a diver without cavern training can do those dives and if so, how to minimize the risks.

The problem here is that you, like some others, are trying to second guess motives and as a result most of your comments do not address central question. The question posed in the OP was to identify the risks associated with diving in the specified environment. I think it is now safe to say that most of those have been identified but if there are some that have been missed then feel free to add them. I've said previously if it makes you more comfortable assume the person doing the dive is adequately trained.

 

[Redshift]

That's wrong. You clearly said you're not trained and don't see the need to be and that other divers had told you it's not necessary in order to dive those caves.
Furthermore, for a trained diver, the risk identification is a normal exercise and it wouldn't be necessary to have such a long thread because of a simple cavern like this. And looking at the list, it's obvious it's for non-trained divers. Many of those points wouldn't be requirements for a trained diver. The risks are the same for trained and untrained divers. You are trying to mitigate those risks enforcing an ideal cave scenario, trained divers mitigate those risks by having the proper training and equipment. One big problem is what happens when those idyllic conditions change? And for some of the points in the list, how do you ensure them?

- Ensure you always have adequate room for easy access to your buddy and your octopus.
- Stay close to your buddy in case of an OOA emergency unless you both have an independent gas supply.

Do the divers know where the buddy's octopus is? Will they ask for air or grab the first thing they see? And that has been shown many times that it happens. (Actually, it happened in my cave course...) How will the diver react if someone takes his reg?
Will this air share and cave exit happen with trim and buoyancy control or will they start kicking up sand and bumping against other divers, the walls, ceiling...?

- Don't dive in caverns where silting can obscure and prevent exiting the cave
- Only dive in caverns where there is no chance of getting lost.

As someone said, it's hard to have places where it's impossible to kick up silt. But I concede you that. I've been in caverns where that would probably not happen, especially sea caves that can even have a rocky bottom, not sandy.
And there are caverns where it wouldn't be hard to find the exit. If the cavern shape is simple, there are big exits, no dead-end tunnels nor connection to a cave. But even so, how would a diver react to being without visibility and bumping against a wall?
And even if these conditions apply to the caves you know, how would you or other divers that dive there then react to the possibility of diving in a different cavern? Trust that it meets all the criteria? Trust the analysis done by someone else? We have seen so many reports of reckless instructors and dive guides... Slowly push the boundaries because the cavern is "almost" like the one you described? Maybe you'd recognize the risks, but there's also the responsibility towards other divers being taken to the caverns.

- Only dive in caverns with adequate natural lighting.

As someone pointed out, cloud cover can significantly reduce the light underwater and even more in a cave. Are you avoiding dives when there's chance of clouds?

- Only dive in caverns with open and ready access to and from all parts of the cavern.

Well, except upwards... and that's what OW divers are trained to do as a last resort and what many have the tendency to do when something goes wrong.

- Avoid diving in caverns with incompetent divers or divers prone to panic.
- Know how to deal with a displaced mask and BCD inflator stuck open.
- Only dive in these caverns if you can maintain neutral buoyancy and fin without stirring up the bottom.

Some divers can, other divers can't. You may know yourself and your usual buddies, but what if there's someone else in the group? And even people you know, have they been tested in an emergency situation in a cave? It may not be obvious how people would react.

You're expecting certain conditions, but conditions can change. You're expecting divers to have a certain proficiency, but some of them haven't been in situations that would show how they'd react and when diving with groups, some divers may not be even known. For some people this can be the first step into diving in other caverns where conditions may not be the same. It may be hard to recognize risks over the internet. And what looks safe for some, may not be for others.

 

[Foxfish]

Interesting discussion to date. Some of you are getting hung up on the training aspect. I never said to assume that the diver did or didn't have training. If it makes you more comfortable, assume they have training.

From post #35. So you clearly have not checked the thread prior to making your claims regarding what I said on this matter.

 

[humuhumunukunuku]

i only fear swim-throughs here in malaysia from april-june when you are likely to come face to face with a titan triggerfish during nesting season with no way to turn around!

 

[Redshift]

That's you changing the premisses when you don't like the answers you get.

One of the reasons for starting the thread was to challenge the thinking that says that doing a cave diving course will somehow magically reduce the risks associated with the kind of diving described in the OP and now by FBK. In our area, those risks can be mitigated by good local knowledge and some simple commonsense guidelines like:

From post #61. Clearly, you haven't been paying attention to what you say. If you think training is magic, keep it that way. You seem to prefer arguing with people than about the clearly explained situations I have highlighted. And I wasn't even in the "no training, no diving" faction, I agree it can be done for some people in some situations.

Several people have pointed out that you are setting a big list of requirements and therefore you are assuming that that's how things will be, and that's a lot of assumptions. What happens when things don't go according to the assumptions? Even with guaranteed conditions in a cavern, it can be hard to know in advance if people have the necessary skills when something happen, how they will react, if they will follow the behaviour listed in the requirements, etc. OW divers know how to share air, that they need to keep close to their buddy, that they have to check their air, how to maintain positive buoyancy on the surface, etc yet how many get lost from buddies and groups? How many run out of air? How many die on the surface with weight belts still on? The fact is that things can happen and listing them or saying "they have to be like this or do this" is not enough to enforce that it will actually happen like that. The training is necessary not only for the planning, risk identification that you are doing and proper behaviour in the water, but also for knowing what to do when things go wrong.

 

[Foxfish]

If you think training is magic, keep it that way. You seem to prefer arguing with people than about the clearly explained situations I have highlighted. And I wasn't even in the "no training, no diving" faction, I agree it can be done for some people in some situations.

The conditions I've outlined are what we normally experience over here. I've also outlined and previously restated the purpose of the thread. At the moment your comments have amounted to little more than ignoring the purpose of the thread and arguing against your twisted version of what said. I call it trolling.

 

[Redshift]

Risk assessment like you are trying to do here is important, but you are failing to notice that identifying a hazard is not enough to become safe. And that is part of the risk as well. You have to 1 - identify the hazards, 2 - mitigate the chances that they will result in incident / accident, 3 - have a plan to deal with them in case of incident / accident.
You are doing 1, but then "forcing" as a rule that divers are able to do 2 and that 3 will not happen.
Saying that divers have to behave a certain way and should do certain things is not a guarantee that they will happen. Training will not only provide the divers with the skills to not create incidents / accidents, but will also prepare them to act when they happen.
I am not saying don't dive / you cannot dive, I'm pointing out flaws of that way of thinking that are not minimizing risk and that you have to account for and you haven't done. You haven't said how you can be sure of the skills and behaviours of divers, how to know the conditions of a cavern before actually diving it, how to proceed in certain scenarios that several people here have mentioned. In some cases what you did was to force those scenarios not to happen. Well, they happen, even to trained divers.

 

[Kevrumbo]

The problem here is that you, like some others, are trying to second guess motives and as a result most of your comments do not address central question. The question posed in the OP was to identify the risks associated with diving in the specified environment. I think it is now safe to say that most of those have been identified but if there are some that have been missed then feel free to add them. I've said previously if it makes you more comfortable assume the person doing the dive is adequately trained.

Here's a special case I posted in another thread as it applies to wreck "swim-thru's", also referred to as a traverse:

The Truk Lagoon Wrecks planning dilemma -especially for the GUE-trained Divers- as to overhead protocol: you will either be with a dive guide who will lead your team on traverses through the shipwrecks' cargo holds, superstructures & engine rooms etc. --all without running line-- or choose to run a reel-line & egress out on reel-line without using a leading dive guide.

The advantage of running a reel-line is of course safety & standard operating overhead procedure as trained; the disadvantage is that you won't have as much bottom time to fully explore the wreck than if you did a through-and-through traverse. In other words, the dilemma will be whether to do "Trust-Me" dives with a Dive Guide or not. . .

The Trust-Me Dive goes both ways in Truk --the Guide is vetting you on the initial easy checkout dives, making sure of your general trim & kicking technique as well as your aptitude & temperament for wreck diving. He's gotta be sure that you won't panic when the rust & silt starts "percolating" all around you. . .!

There will be times where you will be in a tight engine or crew space in a near silt-out; or momentarily lose sight of the Guide around a corner corridor or up through a vertical gangway; or going thru 'Black Hole' caverns -burned out blackened ship spaces that totally suck-out the illumination from your canister light (and where the worst of all zero-viz conditions can occur -"Black Ash Silt-outs"). You have to trust that the Guide knows where you are at all times as well as all wreck egress pathways, and the Guide has to know that you won't make a potential emergency contingency worse by freaking out. . .

A compromise best solution is to have a "Pathfinder Team" --that is a team laying line with a Dive Guide in front leading a traverse through the wreck; and then having other teams come in later following that line to video/take pictures/sight see etc. --and then finally later a "Clean-Up Team" to reel-in the guideline, while traversing back in the opposite direction and winding-up reel-line. . .

 

[MXGratefulDiver]

The wildcard in all of this is what's going on inside a diver's head, and how will that diver react if something doesn't go the way it was envisioned.

Years ago I did a relatively benign swimthrough in Roatan ... I believe it was Calvin's Crack, but it was a long time ago and it might have been a different site. What clearly stands out in memory is what happened during the "overhead" portion of the swimthrough. Now this is a pretty easy swimthrough ... not particularly deep and an overhead only in that, although you can see the surface at all times, there are places where the walls aren't sufficiently wide enough to allow you direct access to it. We were told during the briefing that when it narrows down we must swim through single-file and not try to pass the person in front of us.

It looked easy enough, and everything was going fine till we got into that narrow section. Cheng was in front of me, a couple divers in front of her, and a couple divers behind me. All of a sudden I felt something moving underneath my legs, and realized the diver behind me was trying to get past by swimming underneath me. I stopped and let her go ... she was kicking pretty furiously trying to get out. As she wedged past she managed to whack Cheng in the face, causing her to lose her regulator, and although she retained her mask she flooded it. Fortunately Cheng handles things like that pretty well, and retrieved her reg and cleared her mask, but in the process lost buoyancy control and managed to get tangled up in some wire coral in the wall above her. While I was helping her get out of that the gal who created the issue continued bowling through the divers in front of her, and as soon as she exited the crack ... at about 80 feet ... she bolted for the surface. Fortunately she didn't hurt herself ... nor were any of the people she knocked out of her way injured. But they easily could have been.

There was absolutely no rational reason for what occurred ... this was an easy swimthrough, with a clear entry and exit, in pretty benign conditions. But this gal allowed her "get me the hell out of here" instinct to take control, and that defies rational thought process ... instincts that have developed as a way to keep you alive in a crisis on land can hurt you or anyone around you underwater. She was neither prepared, trained, nor tested on how to deal with those emotions, and they got away from her.

This happens at popular dive areas around the world pretty regularly ... and no amount of discussion on an internet forum can cure it. It's one thing to sit behind a keyboard and play mental games ... it's another thing entirely to be in the water and encounter what might appear to be a completely benign condition that triggers something in your head that threatens to take control of your dive. One of the purposes of training is to help you identify whether or not that gremlin's sitting on your back, and if so how to take control of it when it tries to crawl inside your head. Not everyone will have that problem ... but without some form of in-water testing, how would you know?

... Bob (Grateful Diver)

 

[rongoodman]

i only fear swim-throughs here in malaysia from april-june when you are likely to come face to face with a titan triggerfish during nesting season with no way to turn around!

That's why GUE insists on you having a back kick!