Swim-through or cave?

[Matthias Hoeller]

Hi,

I had an interesting moment yesterday. My wife and I are currently on a scuba holiday in Egypt, diving several Red Sea spots within boats reach from our resort. The local dive center appears very professional and overall well run.

On yesterday's full day boat trip to a nearby reef, during the briefing, the guide announced that near the end of the dive, there would be a "cave" (his own words) that the group would swim through. He described the following features:

- Horizontal "U-turn" shape
- 11meters long swim (36 feet) from entrance to exit
- "single file", so guide leads the way and one diver after the other follows. No space for two buddies side by side
- "one way", so everyone was instructed to enter the "left" opening so as to exit the "right" opening and avoid collisions between divers going in different directions
- relatively shallow, I am not sure but I would guess it is located in about 5 meters (15 feet) depth or even less
- near the end of the dive plan when there may be already some divers with less than 100bar (less than half a tank)
- OWD certification sufficient from guides' point of view
- no additional equipment other that standard recreational open water setup

I appreciated some aspects that I found were professionally handled by the guides:
- the plan was clearly communicated during the briefing, no "surprise cave adventure"
- everyone was explicitly and actively asked for their consent after the briefing
- we said "no", and that was easily accepted without any attempts to persuade us otherwise.

Still, I am not sure how to assess the whole situation. On the one hand, as far as I can see, this part formally qualifies at the very least as a "cavern", but the definition of a cavern forbids the single file restriction, so I guess, formally one could even classify this as a cave for that reason (restriction).

However, in total it still appears to be a reasonably simple and short swim-through, so I can see how the guides decided it would be OK to take OWD certified tourists with recreational gear without any additional training or equipment.

But it makes me uneasy to imagine a single file crowd of divers (no easy access of buddy for redundant air source), of mixed experience levels, with tanks less than half full. What if first diver gets stuck or entangled? Everyone further behind in the single file doesn't understand what's going on. Guide cannot go back to help. Someone in the middle might panick or at least increased breathing rate. Or what if some other divers (from a different group) enters the cave the other way in and causes a blockade?

Any thoughts from the community? How would you assess this? Am I exaggerating the risks or is this as unsafe as it feels to me?

Best,
Matt

 

[Tassi Devil Diver]

Just a simple swim through nothing more nothing less, sure it might make some new divers feel uncomfortable, but they have an opportunity raise their concerns with the DM following the briefing and I am sure other arrangements will be made others will jump at the opportunity. With more experience you will become more comfortable with these sorts of swim throughs.

 

[rongoodman]

If you have to ask, it probably isn't a swim through. The fact that the exit cannot be seen because of the "U-turn" configuration is the defining issue for me.

 

[Capt Jim Wyatt]

Given the overhead, the single file/no turning around component and a "gaggle" of divers going through at once I see a problem there technically. In practice they probably do it every day and have always, thus far gotten away with it.

 

[steinbil]

It's fine until it isn't. I would assume there is no real risk of entanglement or getting stuck, otherwise it would be a real Russian roulette. I also assume there is no possibility of getting lost or not finding the way out. Still, it's a restriction with a group of possibly quite inexperienced or nervous divers in a single file - that is a little worrying. I'd primarily be worried about a nervous diver in the middle of the line, not wanting to continue, but being trapped with divers behind. That could quickly lead to panic...

 

[noserider]

Given the overhead, the single file/no turning around component and a "gaggle" of divers going through at once I see a problem there technically. In practice they probably do it every day and have always, thus far gotten away with it.

Agreed they do it because they always have without incident and these kinds of swimthroughs / mini caves are dived a lot in Europe with OW divers and sometimes are quite tight.

I normally chose to be the tail end charlie in this kinds of situations so if there is a panic ahead of me I can turn around / intervene or help if possible.

 

[rddvet]

Probably not an issue and is likely an easy swim though, but good on you to stand for what you're comfortable with . The first rule in technical diving is anyone can call the dive at anytime for any reason. You basically did that in the pre-dive. Too many people will be nervous about something but don't want to be the one to say no. Good on you for not being too nervous to be honest

 

[Norwegian Cave Diver]

I respect your decision to pass on that part of the dive... But it was 35 feet (your words) and I am 6 feet tall, So 6 of my lengths, assuming 6 feet between each diver... there is you just entering + space + diver + space + diver and and the exit.
I began my interest in cave diving by fluke. We were staying at the Bahia Principe near Tulum Mexico and the dive shop knew me well. Was too windy to go out in the ocean and so they decided to take divers to a Cenote. Dos Ojos (look it up ) I didn't know what that was and they explained and also said I would be fine there. I knew it was going to be an overhead environment and so I decided to go with them. It was a 45 minute dive all overhead and it was INCREDIBLE for me. I instantly knew this is what I wanted to do. That began my training to become a cave diver.

 

[Capt Jim Wyatt]

I began my interest in cave diving by fluke. We were staying at the Bahia Principe near Tulum Mexico and the dive shop knew me well. Was too windy to go out in the ocean and so they decided to take divers to a Cenote

Did they take you into the "cave zone" ?

 

[scrane]

It is a purely personal decision. It sounds like the DM gave an excellent briefing. Swim throughs are usually at the discretion of the diver. Not a big deal.
A good opportunity for PADI to devise a "35' U-shaped Swim Through Certification".