Cave Diving, Cave Exploration and Cave Mapping in Yucatan, Mexico
Taco Express bathroom stall in Austin, TX

The Quest for the Blue Abyss. Part 2.

I made my second cave dive at Pet Cemetery in Sistema Nohoch Na Chich looking for the Blue Abyss and what I discovered is that the map of Nohoch that I have access to, has nothing to do with the lines and cave underwater. As I understand it, the map of Nohoch was created by a large team of people with varying degrees of expertise in cave survey. Therefore, it is notoriously inaccurate. Plus lines change all the time and new discoveries are made. I have ceased to rely on that map and have started to develop my own very nice stick map of the area.

Today’s dive was a big success! It started with an o-ring extruding from an omni swivel when I got in the water and I was doing my predive checks. In less then 100PSI, I had the value shut down. A couple of minutes later, I doffed both tanks, removed the regulator and headed back to the 4Runner to make a repair. Past experience with another leaky omni swivel had informed me that I didn’t have the correct o-rings to repair it. So, I dug in the trusty tackle box and pulled out a replacement 120 degree Scuba Pro swivel. I really like the Scuba Pro swivels for a couple of reasons:

  • Only one dynamic o-ring and it is captured.
  • It has a fixed angle that places the regulator nicely.
  • It is tiny and doesn’t change the weight or hose length dramatically.
  • It seems less failure prone because there is no screw on a dynamic turret holding it together.

So, if you have a choice, go for the Scuba Pro swivels. The repair made, I started my dive. The guys where working in the Cenote again dredging it out, so viz was crap for the first couple of minutes, but it cleared up nicely. This time I went left at the first T. When I got the second T I had a decision to make, and based on the compass heading I elected to go left. The line passes through an extensive area of open water dome and then plunges down a sandy hill into the cave. Immediately I was excited. The cave was really beautiful. After a reasonable swim, I came to a nasty looking restriction. My research later revealed it is called, “Tanks on, tanks off ” It is a fantastic window in the rock face. It is smooth all the way around. From my direction you have to pass through it by going up and onto a bedding plane. I looked at it for a second, unclipped my right tank, swung it out in front and passed it with my shoulder dragging a little. SIDEMOUNT ROCKS!

My first impression was it would be a challenge in backmount or impossible if you are a big guy. The only hope would be to go through on a funny angle. However, returning through it in zero viz in backmount sharing air would have been a supreme challenge. To be honest, returning through it in sidemount under stressed conditions would have been a challenge because there is limited room to setup on the other side. So I added a little padding to my gas to ensure a stress free exit.

As I continued the dive taking notes and enjoying the breath taking formations, I realized the line changed type and I hadn’t noticed. The line was a thick white line, the thickness of kermantle, and now it was knotted exploration line. This startled me for a moment and I had to make a decision to back track and note the line change and confirm I was on the right line or continue on and trust everything was ok. I decided to back track and put those devils to bed. Over an arrow, up through a minor restriction and there was the junction. It was about 2 minutes back. I took a mental note and continued the dive.

It is this kind of realization that starts to build mental stress. The feeling of not knowing or feeling lost is insidious. Couple the change in line, the lurking idea you might be on the wrong line and another crisis of your description and you have a recipe for a full on fear fest should something nasty go down. Progressive penetration and awareness are keys to survival. There is no reason or goal that should drive you to skimp on something as small as a two minute back track to confirm your location.

I swam to the end of the line. It took me about 40 minutes and less then 1000PSI with my back tracking and extensive note taking. The line terminated just a couple of feet short of another line, which I believe to be the Diaz Line. The return swim took about 30 minutes and about 500PSI. There was a section on the return swim with decent flow that slowed me down. But it is only a hundred or so feet long. I wonder where all that water is coming from and where it is going. Because it doesn’t pass through “Tanks on, Tanks off”.

When I got home I drew my stick map from two days of diving. It is a supremely satisfying feeling to look at the new map and know you have been there and you have a foundation for future dives. I have to thank Patrick for that. He is the one that got me to be more disciplined in my note taking and drawing. And he gave me a system.

1 comment

1 Barbara/San Francisco { 11.30.11 at 10:32 am }

Nice report, thank you. ‘Glad you put the “devils to rest,” it was the only thing to do. I’m looking forward to doing this dive again next month.