Cenotes and Cave-vs-Cavern

[ae3753]

Here's another great thread from the past:

cenotes experience/certification?

 

[bamamedic]

I just got back from a trip to the Riviera Maya and did several cenotes dives while there. They were awesome!!

I felt very comfortable with the dive but I didn't feel comfortable about some of the others in the group. I can only imagine how bad some of the divers might be that visit these beautiful places to the detriment of both the cave and diver.

One of the DMs leading the dive pointed out that we were doing "cavern" dives and not "cave" dives so it was "OK".

Are there formal (PADI, SSI, NACD, etc) or generally accepted parameters that differentiate cavern diving from cave diving? Or was that just the operator trying to rationalize why it's OK to take inexperienced divers into a cave for a buck? Or maybe both?

There are indeed formal definitions of cavern vs. cave, but a good way to check is to cover your light. If you can still see daylight, you're still in the cavern. If you can no longer see the glow from the cave entrance, then you're in the cave.

 

[netdiver]

In addition to visible entrance/exit, restriction on depth & penetration, NAUI also has the important restriction that two divers must be able to swim comfortable abreast.

Interesting... We were expressly forbidden to swim in parallel to another. We were required to swim in a line or staggered at most.

 

[netdiver]

Here's another great thread from the past:

cenotes experience/certification?

Thanks. I did a search and didn't find a post.

 

[MauiScubaSteve]

There are indeed formal definitions of cavern vs. cave, but a good way to check is to cover your light. If you can still see daylight, you're still in the cavern. If you can no longer see the glow from the cave entrance, then you're in the cave.

You can easily be over 200' from the surface and still see light so by diving definitions it is considered not a cavern. The light could easily be coming from small cracks no free diver could fit through so by diving definitions it is considered not a cavern. There are most likely plenty of widows and orphans of divers who used the cover your light rule.

Since many participants do not seem able to follow links in threads before posting in threads I will quote a NSS-CDS Cavern certified diver from the first link in this thread;

I'd like to see the varied definitions differentiating cavern from cave diving. I completed Intro to Cave in Spring of '00, and as I understand it, NSS-CDS has changed their definition since I was trained. At that time, NSS-CDS and IANTD were similar enough that I was offered cards from both agencies.

From my NSS-CDS Cavern Diving Manual, cavern diving in standard recreational scuba gear follows these limits;

Direct Sunlight Zone - diver can see the opening (entrance/exit). If you can not see the opening but it is not pitch black, you are in the ambient-light zone. When it is pitch black and you can see nothing without lights you are in the zone of total darkness. Cavern diving is only in the direct-sunlight zone.

130' Maximum Linear Distance from the Surface - Cavern divers must stay within a linear distance of 130' to the surface. Linear distance includes the depth of the entrance plus the distance of penetration. Examples; 30' deep entrance plus 100' penetration, 50' deep entrance plus 80' penetration, 70' deep entrance plus 60' penetration.

70' Max Depth - Below 70' air reserves for dealing with emergencies are too limited and the margin for error becomes too critical.

No Restriction - Buddy teams should be able to comfortably swim side by side. If divers have to swim single file due to localized narrowing that is considered a restriction. Cavern divers are not permitted to pass through restrictions in part because sharing air with standard scuba through a restriction is nearly impossible.

40' Minimum Visibility - The minimum visibility acceptable for cavern diving is 40'.

No Decompression Limits - Cavern divers should stay well within the no-deco limits. When cavern diving, bottom time is the time from leaving the surface until returning from the cavern to a depth of 10' in open water(not ending at start of ascent). Most experienced cavern divers stay within 80% of NDL limits, to allow for any unexpected delays during exit.

Air Supply Limitations - One of the three leading causes of death in underwater caves is failure to reserve adequate air for exiting. This requires at least as much air in each cylinder as both divers (buddy team) used coming in on the two seperate cylinders (basic rule of thirds).

If you are in any of these following situations, you are technically in cave diving territory; ambient-light zone or zone of total darkness, more than 130' linear from surface, deeper than 70', past a restriction less than 2 divers wide, less than 40' visibility, more than 3 minite required saftey stop. Violating the rule of thirds does not put you in cave diving territory, you are just very foolish.

I'd like to hear from more than just North America; CDAA (Australia), CDG (Great Briton), IANTD, TDI, GUE, NACD and any I've missed. Not really interested in what PADI, NAUI and similar mainstream agencies have to say.

 

[netdiver]

Since many participants do not seem able to follow links in threads before posting in threads

Is this a perhaps a hasty misinterpretation of my giving thanks for the link? I thanked the poster for the link and mentioned that I did attempt to do a search without fruit before posting here. I did in fact follow and read the link. That's why I gave him "thanks" and didn't ask anymore questions.

 

[ReefHound]

Interesting... We were expressly forbidden to swim in parallel to another. We were required to swim in a line or staggered at most.

You should be able to swim side by side if necessary, but your guide wants you to swim single line. He wants to be able to easily see the last diver in line. He wants adequate room should he have to swim back to the last diver. No conflict here. Just as you should be able to do an air sharing ascent, your guide might prefer you not do that unless it's an emergency.

 

[TSandM]

In general, no one should dive in a cavern or a cave who isn't trained to do so. The cavern tours in Mexico are an exception to this rule, and are run with an amazingly good safety record. In large part, this is due to a set of rules that were developed and voluntarily adopted by the cave diving industry down there. Those rules include a good briefing on buoyancy and trim and cave conservation before the dive, and a guide who is a DM or instructor, full cave certified, and diving in cave gear. There are to be no more than 4 divers to a guide, and everyone is to have lights.

Unfortunately, I have seen in my last trips down there a number of groups where those rules were not followed, and I think it's a bad omen for the safety record in the future.

There are quite a few people who think these dives are not a good idea, anyway, and that no one should cavern dive, tour or not, who is not trained. There are some good arguments in favor of this position.

Hope that helps answer your original question.

 

[Paladin]

Hmm. How does Ginnie Springs fit in? I'm thinking about going there next summer.

 

[MauiScubaSteve]

Is this a perhaps a hasty misinterpretation of my giving thanks for the link? I thanked the poster for the link and mentioned that I did attempt to do a search without fruit before posting here. I did in fact follow and read the link. That's why I gave him "thanks" and didn't ask anymore questions.

Well I have two points to make here, although I am not worried about collecting thanks; please review post #7, and by quoting bamamedic before I made the comment you quoted, I was pointing my comment at bamamedic.

But now that you have pointed at yourself, if the shoe fits....