Semi-Cave: Is this dangerous?

[Dizzi Lizzi]

One thing to remember is it doesn't matter how good a diver you are or how comfortable you are, it is the divers around you that could cause the problem. If one panics in an overhead or kicks up the silt, are you confident you can get out?

Right on! It's not you alone. What if multiple panic occur? Someone grabs you... Just me thinking in my "what could go wrong" mind frame. This scenario is making me plan out how I would handle it... Yes I prob would do the dive, one aspect of my plan would be that my position would be right behind the DM most likely (I would say I had reservations and to do it I need to be by the guide) There are soooo many variables when you dive, it's crazy making.

 

[Doby45]

 

[Storker]

I think you have to look at each overhead environment on its own merits. If you are in a hard floored semi cave with plenty of light and minimal penetration, I don't think it would be too dangerous.

That's all well and good. However, given the OP's experience, they is probably not competent to do a proper, competent evaluation of the environment. When I was fairly newly certified, I made a decision: No overheads. Period. And don't come with the hyperbole about swimming below an anchor chain, that's just silly. However, I realize that without cavern or cave training, I don't know what I don't know about overheads and prefer to stay the heck out of them. I've pissed off at least one guide with that attitude, but since I'm paying for the party, I'm going to decide on the music...

Erring on that side is safe. Erring on the other side is very, very dangerous, particularly since quite a few dive guides seem to have a very cavalier attitude towards taking OW certed patrons into overhead environments. Occasionally, that ends very, very badly.

 

[Storker]

It was indeed a very easy dive, in fact my most pleasant dive so far with very little variation in the depth. There was silt, but it didn't go very high when kicked up. The "we know what we are doing" attitude was pretty strong. We were advised to not look at our gauges and just let the instructor handle these things lol. I felt safe and Im not complaining[...]

You might consider reading Who is responsible for what?. In fact, I recommend that thread very strongly.

 

[kr2y5]

If it's only 30 feet long, 30 feet deep, and within the light zone at all times, doesn't it fall with a fairly wide margin under the definition of a "cavern", rather than "cave"? My understanding has been that for cavern dives, it's more or less generally accepted that no formal training is required as long as one has a competent guide, and certain regulations, e.g., about group size are followed.

 

[Neilwood]

That's all well and good. However, given the OP's experience, they is probably not competent to do a proper, competent evaluation of the environment. When I was fairly newly certified, I made a decision: No overheads. Period. And don't come with the hyperbole about swimming below an anchor chain, that's just silly. However, I realize that without cavern or cave training, I don't know what I don't know about overheads and prefer to stay the heck out of them. I've pissed off at least one guide with that attitude, but since I'm paying for the party, I'm going to decide on the music...

Erring on that side is safe. Erring on the other side is very, very dangerous, particularly since quite a few dive guides seem to have a very cavalier attitude towards taking OW certed patrons into overhead environments. Occasionally, that ends very, very badly.

I quite agree with you (as my more recent posts tend to suggest). I am the same in that I don't know what I don't know therefore I don't know what could hurt me (although I have a few guesses like the panicked diver, OOA, silted etc as mentioned in my other posts).

There is a lot of ocean out there and I would rather see those bits I am trained for and that I am certain are within my training and experience.

 

[FinnMom]

And even if you are fine, if the dive guides are taking relatively inexperienced people into an even remotely challenging experience, you never know when someone near you is going to get too far out of their comfort zone and suddenly do something unfortunate.

Mildly challenging experiences are fine when you feel ready, but it should be your choice, not some guide's surprise. It's also best not to get into new/tight/&challenging situations with divers you don't know from Adam.

Learn from other's mistakes. For example, Diving My Way - Scuba Steve's (the "not-so-Original") site about SCUBA Diving

 

[Lorenzoid]

In the vein of "I can't define it, but I know the difference between a swim-through and a cave when I see it," the problem is that unless a diver has seen a video of it or has some other way to know how long it really is, how dark it really is, how wide it really is, etc.--not just the dive guide's optimistic estimates during a briefing--he has no way of making an intelligent decision whether to go there or not.

 

[uncfnp]

I may get some flak for this but now having done ocean swim throughs, cenote "caverns" and some very limited cave, to me there really is no comparison between swim throughs and caves.

I know the risks in cave but humor me. What are the specific risks with these swim throughs? Has anyone died or even been seriously injuried in one? Or am I misunderstanding the OP's post?

 

[boulderjohn]

owever, I realize that without cavern or cave training, I don't know what I don't know about overheads and prefer to stay the heck out of them.

doesn't it fall with a fairly wide margin under the definition of a "cavern", rather than "cave"?

It's much closer to a cavern that a cave, but it really isn't either one. While there is no official definition for a swim through, that is what it is through common understanding.

This lack of information about the differences in overhead environments is why I created a course called "Understnading Overhead Environments," which goes through the characteristics and dangers of the various kinds. It describes the kind of training needed for each and hopefully helps divers make a decision on a question like this one.

In the course, you would learn to look for some defining characteristics for evaluation. In this case, you would consider that there are two visible exits within reasonable reach and good ambient light. You would consider that it is not very deep. You would look for the potential for silt to destroy visibility, and you would check for restrictions--can two air sharing divers go through the exit without difficulty at the same time? You learn to ask questions about that before entering any overhead and deciding whether or not your training and experience is up to the task. (And, yes, swimming under the anchor chain should be within the skill set of every diver.)