Mar 29, 2008
As I mentioned earlier in the week, I was tied up the first four days of this week completing my IANTD Full Cave Diving class with Steve Bogaerts.
A couple years ago I completed my Cavern Diving and Intro to Cave Diving certifications through the NACD with Michael O'Leary. I did both of those certifications in Florida (another part of the world with lots of water-filled caves underground). I thought the class was interesting and taught me a lot about safety and good diving technique, but I wasn't wild about the caves in Florida. They're smaller, tend to have a decent amount of water actually flowing in them (so it's a little more challenging to swim against), and they were never dry caves, so there aren't any stalactites or stalagmites to see.
The Yucatan Peninsula in Mexico is one of the best places in the world for cave diving. Some several thousand years ago, when the oceans were lower, the caves here were dry and developed beautiful formations like the ones seen in dry caves today. When the sea level rose, the caves filled with water.
One of the main reasons we moved here was so that Hans could dive in the caves. Luckily, I find the caves here really beautiful and some of them are really large (Florida's caves can be fairly small). Since we've been here I've gone cave diving once or twice a week with Hans and I've started to become a little more comfortable with the procedures for cave diving. We were conservative, following the rules regarding my limitations as an Intro to Cave diver- we used only 1/6 of the air in our tanks, didn't make any navigational decisions and didn't go through any restrictions. After a few months, not being able to dive on 1/3 of my gas and not being able to make any turns or jumps in the caves started to become a pain in the butt. So I signed up for a Full Cave class with Steve Bogaerts (one of the best instructors in the world- in my opinion).
The first day of class was spent reviewing my gear and how I had my harness set up and practicing skills in the open water. We practiced various propulsion techniques (or kicks, if you will) and did various zero visibility exercises (eyes closed, simulating a silt out or total light failure). Steve laid a convoluted course with the reel in the Cenote at Ponderosa (Cenote El Jardin del Eden) and we had to follow along it sharing air and with no visibility. We then took these skills into the cave and did a simple dive at Ponderosa that involved lights out, air sharing on the way back out. At some point along this dive I flooded my Sunto Mosquito dive computer, so that meant that I had to complete the rest of the class with just a bottom timer and watch. (The Mosquito will now cost me about $300 US to replace. ugh)
The second day of class we met at Taj Mahal and went over the theory behind navigation, when to place personal directional markers and personal non-directional markers on the line to help you when you exit. Then we did a couple dives at Taj Mahal that involved making simple navigational decisions. We also had to exit lights out, sharing air and following our navigational decisions.
The third day of class we met at Minatauro, a smaller cave that has lots of restrictions (places that force you to travel single file). I really love Minatauro. It's a seriously beautiful cave. Some caves are so big that your flashlight can't illuminate the edge of the room you're in. Minatauro is the opposite.
Anyway, Minatauro has a circuit, so we went over the theory behind how you do a circuit safely and then we put it into practice. Our first dive we headed to the double line arrows and made a jump to the left and continued on until we reached our time limit and placed a personal non-directional marker (cookie) on the line. This marked how far we got along the line from one direction.
On the second dive we stayed straight at the double line arrows and continued along the line until we ran into our cookie from the first dive. Based on our time and gas consumption limits, we were able to determine that we had enough time and air to continue along the circuit. So we picked up our cookie and followed the line out, taking up our jump reel when we got to the place we had jumped left on the first dive. Very cool.
On the fourth day we went to Sistema Najaron at Cenote Cristal, south of Tulum. The caves south of Tulum are very different from the ones north of Tulum. This particular system is fed by a swampy area, so lots of Tannic Acid (the weak acid that is formed by decaying plant materials) floats in the water and stains all the formations (and even the line in places) black. It is very psychologically challenging compared to white caves. In a white cave the light bounces around off the walls and makes the whole place glow. In Najaron, the black walls just suck the light up. It's VERY dark.
At Najaron we practiced complex navigation with the added element of depth and decompression. The whole system is fairly deep there, so we were able to do shorter dives (which was good because cave water ain't warm). We carried tables with us so we could re-calculate our decompression obligation if our dive plan changed. Luckily for us on both dives it did change, and changed in our favor, so we had to spend less time decompressing at 10 feet than we had planned to in our original dive plan.
On the second dive I had to do a lost line drill. Steve had me close my eyes and shut off my primary light. He then led me off the line and placed my hand on a rock for me to begin the drill. He had given me 15 minutes to find the line again in the darkness, because if I had really lost the line I would be on a time limit as well. I tied off to the rock he had positioned me on with my safety reel and then did a secondary tie off to establish my starting position and I headed off in one direction looking for the line. After a little while I wasn't able to find the line so I headed back to my starting point and picked another direction to head in. This time I did find the line and I clipped my spool to the line in the direction I thought was out and began exiting. Steve patted me on the head to signal the exercise was over and it turns out I was on the line and headed in the right direction, but it had taken me 10 minutes to find the line.
All in all, the class was VERY good. I'm really glad I took it with Steve, too. I had to wait a little longer than I would have if I chose to take it with another instructor (because Steve is really busy) and I paid more, but the instruction was top notch. He manages to give you constructive criticism while also reinforcing what you did right, so you don't leave feeling like you're an idiot or you'll never be able to do whatever he asked you to do. Hans said he also raises the level of the class so it corresponds with your ability level (he took Steve's Side Mount class, too) and only teaches you what you can handle, so since I was already ok with cave diving he focused on technique and smaller details.
I have taken dive classes before with instructors who have a passion for teaching, but not diving and I have determined that it is imperative to learn from someone who has experience diving using the techniques they are teaching. Steve has been living in Mexico for something like 9 years and has been diving since he arrived. He was already a diving instructor before he left the UK, so he picked up teaching cave classes shortly after he arrived. But not only is he a good teacher, he is also a cave explorer and has gone on various surveying expeditions. In fact, the day before class started he had been bushwhacking his way through the jungle looking for new cenotes.
Hans had issues with his primary light to no end, which I'm sure he will document on his blog, but suffice it to say, Dive Right HID lights suck.
Now, with all this new diving under my belt... I'm going to the beach!