Canyons are fun

[FPDocMatt]

3 people died this weekend doing a "safe" cavern dive in the Cenotes in Mexico.

Caverns and caves are overhead environments and divers should have special training enjoy them safely. Caverns historically have been considered a "gray" area by some, but IMHO these deaths underscore the necessity of training.

Yeah, just swimming through the canyons at Grand Cayman I noticed a diver in front of me get snagged on an outcropping. It was her regulator hose. She patiently stopped, looked to see what the problem was, reached back and released herself. But it goes to show that even in a relatively benign environment problems can happen.

Does my OW/AOW/RD certification qualify me to go into a cavern? I kept asking the people on my trip if these "tunnels" were something I was qualified to do. Nobody seemed to know or care. They were about 12 feet long, and you could clearly see the light at the end of the tunnel from the other opening. But the total diameter of each tunnel was about 6-7 feet, so they were pretty tight. I only went through with a buddy. I know this is considered a cavern, not a cave, since you can see the surface light.

Caves and caverns can be absolutely beautiful, but I would really strongly encourage overhead training for anyone who feels a "call." I personally have never once looked back

Hm, I wonder if there's a cavern diver course in Cozumel. How far are the cenotes from the place we'll be staying at Invade Cozumel? Is the visibility good in the water of the cenotes?

 

[rongoodman]

The cenotes where most of the guided dives take place are across the strait, south of Playa del Carmen. Many of the dive shops in Playa will organize trips down to the cenotes, and Playa is only a ferry ride away from Cozumel. Unless you're actually in the disturbed halocline, I'd guess the vis to be at least 150', probably more. In the big chambers, I've run out of light from my 21W HID before the viz went away.

 

[diversteve]

How far are the cenotes from the place we'll be staying at Invade Cozumel?

There's a trip planned.

Cenote “Double Underground” Trip – 20 spaces available

Cost- $155/per person
Does not include the cost of the ferry, about $15 USD each way. Gratuities not included.


A full-day excursion to dive two cenotes on the Yucatan mainland! These magnificent caverns offer crystal-clear visibility and the world's best freshwater diving.

Includes includes transportation from Playa del Carmen, 2 cenote dives and snacks, tanks, weights & lights.


9:00 am - participants take the 9:00 AM ferry from Cozumel to Playa Del Carmen.
9:30 am - Aquatech meets you at the pier in Playa Del Carmen and provides roundtrip transportation from the Playa Del Carmen ferry pier. Dive two different cenotes.
6:00 pm - back in Playa del Carmen for the ferry back to Cozumel.

http://www.scubaboard.com/forums/in...432-whaleshark-cenotes-excursion-details.html

 

[rivers]

Yeah, just swimming through the canyons at Grand Cayman I noticed a diver in front of me get snagged on an outcropping. It was her regulator hose. She patiently stopped, looked to see what the problem was, reached back and released herself. But it goes to show that even in a relatively benign environment problems can happen.

Does my OW/AOW/RD certification qualify me to go into a cavern? I kept asking the people on my trip if these "tunnels" were something I was qualified to do. Nobody seemed to know or care. They were about 12 feet long, and you could clearly see the light at the end of the tunnel from the other opening. But the total diameter of each tunnel was about 6-7 feet, so they were pretty tight. I only went through with a buddy. I know this is considered a cavern, not a cave, since you can see the surface light.



Hm, I wonder if there's a cavern diver course in Cozumel. How far are the cenotes from the place we'll be staying at Invade Cozumel? Is the visibility good in the water of the cenotes?

At this point Matt, I would suggest laying off the courses for a bit and just dive. Get comfortable in various open water conditions first. You're still a beginner, just dive. Enjoy it. Yes courses are good to take, but you also need some real world diving experience, without an instructor. When it hits in the fan in an overhead, where you can't directly ascend to the surface, you need to be able to keep your cool and sort it under water.
In the future, if you want to go down the cavern/cave route, do your research. Pick an agency and an instructor renowned for technical training (I would not suggest PADI for this in all honesty). But right now, you just need to dive. And enjoy it.

 

[lv2dive]

Does my OW/AOW/RD certification qualify me to go into a cavern? I kept asking the people on my trip if these "tunnels" were something I was qualified to do. Nobody seemed to know or care. They were about 12 feet long, and you could clearly see the light at the end of the tunnel from the other opening. But the total diameter of each tunnel was about 6-7 feet, so they were pretty tight. I only went through with a buddy. I know this is considered a cavern, not a cave, since you can see the surface light.

NOTE: A while back, I did have a similar question (related to swimthroughs on wrecks) for which I had a hard time getting an answer (wasn't on SB at the time). I am not an instructor with any knowledge of exact rules except the bolded statements below, but this is what I have gleaned in general...

There are two different questions inherent in what you are asking, I believe. OW/AOW/Rescue certifications do NOT certify (or qualify) anyone to dive in cavern, period. However, swimthroughs are a different story. I do believe that it's commonly accepted that OW/AOW certifications would allow diving in a swimthrough - which can have many different definitions but generally speaking:
- the other end (exit) can be seen from the entrance
- the diver is never further than their certification level from the surface (so if they were at a 20 foot swimthrough at a constant depth of 90 feet or so, that'd be "acceptable" if they were certified to 100 feet - but if the swim through was at 100 feet - it would not be appropriate because at times, that would be up to 110 feet from the surface).
- two divers could fit through any area of the swimthrough

I am not saying that is the be-all end-all definition of swimthroughs, nor am I endorsing going through swimthroughs without overhead training . However, if there is gray area, that is where I believe it falls, and choices regarding swimthroughs should be made at the individual level based on the swimthrough itself, as well as the individual's experience and skill level.

 

[Token]

Cenotes can vary a lot in the degree of overhead you encounter. It probably wouldn't be too hard to find dives that avoid tunnels and swim-through areas, but still give you a taste of the vistas available to divers.

 

[rongoodman]

Other than diving in the open pools, the cenote tours are definitely in an overhead environment. The daylight you're supposed to be in sight of might only be a pale green glow when you've covered your light.

 

[lionfish-eater]

Cenotes should definitely not be someones first encounter with overhead spaces. Short swim thru's are where one should start. Here is a short clip to give you an idea of a cavern dive. At almost all times we were further from open surface then I felt comfortable with, but still within the guidelines for AOW cavern tour. The areas in the video where the ceiling appears flat and black are air domes that can be safe to surface in. I am good at mental mapping and was very focused on our location and the nearest air pocket or exit. Fascinating dive and I will return to dive others. My situational awareness, equipment checks, tolerance for error and willingness to call or cancel a dive are much higher than open water. I am also much more picky about who I will choose to guide my cenote tours. To name names, Scuba Playa, never again. Speleotech, any day of the week and twice on sunday.

[vimeo]35518349[/vimeo]

 

[lowviz]

Matt, still trying to figure you out. Looking for a little bit more excitement? Forget caverns for now!

Notice the cute ramp near the center of the pic. Kindergarden entry and exit. Parking within arm's reach. PM me, we do a night dive in Belmar basin? (this area is too busy for you during the day) I owe you a beer if you hit 15'. Lots of night life, I'll drag the flag...

final offer.

 

[FPDocMatt]

- the diver is never further than their certification level from the surface (so if they were at a 20 foot swimthrough at a constant depth of 90 feet or so, that'd be "acceptable" if they were certified to 100 feet - but if the swim through was at 100 feet - it would not be appropriate because at times, that would be up to 110 feet from the surface).

Well now that's interesting. You add half the length of the tunnel to your actual depth to get your effective depth.

- two divers could fit through any area of the swimthrough

This definitely does not describe the swim through which I navigated at Grand Cayman.