Swim throughs - what could possibly go wrong?

[Foxfish]

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.

I'm interested to know the dilemma here for GUE trained divers. Are they taught to always run a guide line when entering an overhead environment such as the one described in the OP.

---------- Post added February 13th, 2014 at 08:47 AM ----------

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.

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)

Thanks for the story Bob. Agreed. A panicked diver is a significant risks in both open water and in an overhead environment. It's worth thinking about how you would mitigate then risk. The story gives some clues.

- Be well drilled in things like mask and regulator recovery;
- Keep a reasonable distance from other divers and avoid confined spaces especially when you don't know the other divers level of competence; and
- Keep a watchful eye out for signs of a panicking diver.

 

[Storker]

Your list is becoming pretty long now. I'd like to suggest a much shorter and simpler list:

• Don't dive overhead environments unless you have the training to properly evaluate the risks and sufficient skills to mitigate those risks (i.e. don't do it unless you're cave/cavern trained)
• Don't dive overhead environments with people who don't have sufficient skills to mitigate those risks (i.e. don't dive with them unless they're cave/cavern trained)

That works for me, but then I'm a firm believer in the KISS principle...

 

[nimoh]

I think the bottom line is that it is much easier, and much more clear to say "don't go into overheads" rather than listing a bunch of parameters that have to be met, and are subjective.

For example,
How dark can it be before you are beyond the daylight zone?
How coarse does sand have to be before it will not present a silting danger?
How short does a side passage have to be in order to not present a navigation hazard?

 

[MXGratefulDiver]

How short does a side passage have to be in order to not present a navigation hazard?

Not very long at all, depending on the diver's awareness and navigational skills ... and just because you can see daylight doesn't always mean you can reach it by going that way ...

... Bob (Grateful Diver)

 

[nimoh]

Not very long at all, depending on the diver's awareness and navigational skills ... and just because you can see daylight doesn't always mean you can reach it by going that way ...

... Bob (Grateful Diver)

that was my point.

A side passage that hits a dead end at 2 feet is not a navigational hazard, probably not even at 5 feet, but at what point is it a problem?

When you start into a swim through you can see the opening if you look behind you. The further you get in, the darker the opening gets, but at what point do you stop going in (safely). 10 feet? 20 feet?

It just seems more simple and more clear to say don't go into overheads without proper training.


Incidentally, I recently did a dive at Jackson Blue and there were a lot of fish hanging out at the opening. When we were still only 10 or 20 feet from the opening, the fish blocked almost all of the daylight

 

[MXGratefulDiver]

I recall when I did my cave training at Ginnie Springs swimming into a small side passage coming out of Devil's Ear (just as you start up the vertical part). It's only a few feet deep, but enough to confuse the unwary ... and once in, the flow wants to keep you there. For an experienced diver, it's nothing ... for someone who's never experienced it before, it can be a bit of a shock ...

... Bob (Grateful Diver)

 

[tursiops]

Note to self: don't dive with Foxfish or anyone else who already knows everything.

 

[nimoh]

I recall when I did my cave training at Ginnie Springs swimming into a small side passage coming out of Devil's Ear (just as you start up the vertical part). It's only a few feet deep, but enough to confuse the unwary ... and once in, the flow wants to keep you there. For an experienced diver, it's nothing ... for someone who's never experienced it before, it can be a bit of a shock ...

... Bob (Grateful Diver)

You may be referring to the catacombs, and if so, there is also no main line in there.

I didn't actually consider flow as an issue for a swim through, but I guess it could be an issue in some places. However, I don't consider Devil's Ear to Devil's Eye to be a swim through, although I've heard some refer to it as such.

 

[boulderjohn]

However, I don't consider Devil's Ear to Devil's Eye to be a swim through, although I've heard some refer to it as such.

I have heard people who are not cave trained describe it as such. There was a thread in which such a person claimed it was a no brainer swim through that could be done by anyone easily. He had not yet done it--he was just telling people he intended to give it a go.

It sure looks easy from the surface. If you look out from the steps, the eye is right there in front of you, and the ear is, what, 50 feet to the left? All you have to do is head in through the eye and keep left to go out the ear, right?

There was an open water diver who is believed to have tried that a couple of years ago. The assumption is that he went in through the ear. He was probably very surprised at how long that journey was, and he probably never realized that the entrance form the eye loops around the entrance from the ear. So when he took the tunnel from the left, he was probably surprised to find himself in the catacombs instead of exiting through the ear. The catacombs is quite a maze, with a silty floor and no line. Anyway, that's where his body was found, so we can only guess how he got there.

 

[nimoh]

I have heard people who are not cave trained describe it as such. There was a thread in which such a person claimed it was a no brainer swim through that could be done by anyone easily. He had not yet done it--he was just telling people he intended to give it a go.

It sure looks easy from the surface. If you look out from the steps, the eye is right there in front of you, and the ear is, what, 50 feet to the left? All you have to do is head in through the eye and keep left to go out the ear, right?

There was an open water diver who is believed to have tried that a couple of years ago. The assumption is that he went in through the ear. He was probably very surprised at how long that journey was, and he probably never realized that the entrance form the eye loops around the entrance from the ear. So when he took the tunnel from the left, he was probably surprised to find himself in the catacombs instead of exiting through the ear. The catacombs is quite a maze, with a silty floor and no line. Anyway, that's where his body was found, so we can only guess how he got there.

I remember that thread

I believe the plan was to dive off of a boat to avoid paying park fees at Ginnie, and to avoid Ginnie's rules.