Category — Cave cartography

I had the great pleasure of diving on the last day of December 2010, the last day of the year, and what a great dive it was. It was a very nice day, almost no clouds, balmy 27 C or so in the shade. With little regret I was thinking about the people living in snow storms along the U.S. East Coast or Central Europe where at this point a lot of airports, highways, Autobahns & train stations where closed due to the snow and ice. The water temperature in the Cenote was as always 24 C and visibility of over 60 meters.

Cenote Pet Cemetery

The day before the last day of 2010 I started diving with Jirky and Kirsty in Cenote Dos Ojos, both are avid Rebreather divers from Finland, using the JJ CCR Rebreather for all their diving they do and thus brought their Rebreathers to Mexico to do guided cavern diving. Besides having fun diving the beautiful Cenotes they were going to decide if they would like to take a CCR cave diver course in the future.

Cenote Pet Cemetery

When it came to decide where we are going to dive the last day of the year we decided to go to Cenote Pet Cemetery, part of the Nohoch Nachich cave system. Reason to go there was the high traffic at Dos Ojos as we are in peak season. Pet Cemetery is out of the way, far in the jungle and no snorkelers go there, at least not a lot of them. The Cenote is beautifully located deep within the jungle with high trees all around. The dry section of the Cenote itself is densely vegetated with palm trees. The cave itself is white with lots of Speleothems. A beautiful setting, very calming, very quite.

Cenote Pet Cemetery

Cenote Pet Cemetery has its name from cave explorers Mike Madden and Eric Hutchinson who when finding and surfacing in the Cenote for the first time during a cave exploration dive in search for a connection between cave systems Dos Ojos and Nohoch Nachich where looking at all the animal bones laying in the Cenote. Eric told me that Mike said it looked like a Pet Cemetery, thus the name.

When Jirky, Kristy and me rolled up to Pet Cemetery on that last day of 2010 we met Christine and Etienne, both local dive guides, who shared with us the last of the year dive experience.

Slowly we got ready and prepared our Rebreathers. Jirky and Kristy both dived their JJ CCR while I was on my Megalodon CCR. The first dive was done clock wise along the cavern line enjoying this beautiful white and decorated cave. Awesome. No camera was taken on the first dive to go for an orientation to the dive site and enjoy the dive without the burden of taking images.

During the surface interval just before the second dive we decided to bring the camera. Both JJ’s got rigged with slave strobes during the surface interval to lighten up the cave a bit behind the divers to give it more depth. I had two more strobes on my housing to lighten up the front of the divers.

Cenote Pet Cemetery

Off we went for our second dive of the day in a counter clockwise direction while I was shooting away, taking photos as we went around the Cavern tour loop. As we terminated the dive I took some half over half under images in the open water area right next to the platform and stairs.

Cenote Pet Cemetery

Matt

Most cave divers may wonder at the beauty of cave maps and may even use them for cave dive planning but few have learned how to make cave maps. I recently taught yet another survey and cartography cave course with Dirk from Germany. We both used CCR Rebreathers as our primary breathing device during the survey portion of the training program. The goal at the end of the program is to have a published map in your hand, made from your survey data.

cave cartography

Most people would think cave map making and the process of surveying is only for cave explorers but if you have a cave in your neighborhood that is already explored, if there are already permanently guide lines installed but no cave map does exist you many want to consider a survey and consequently producing a cave map. Permanent guidelines do not have to be taken out in order to conduct a re-survey. Knotted line can be used for the distance measurement or fiberglass tape for greater accuracy. The NSS-CDS published a great book called Underwater Cave Survey by John Burge with all the details needed to survey and cartography.

Besides cave divers for dive planning there are other parties who may show interest in cave maps might be the land owner for him to see what he has and locations of potential wells, local governments to decide where certain installations such as gas stations and landfills may not be placed, developers to decide where not to construct due to danger of collapse and environmental agencies for natural reserve planning just to name a few.

cave cartography

A cave survey is a slow process and there are at least two ways to go about it 1) survey in and 2) survey out. 1) During the survey in technique the first diver is laying the survey line and the second diver is taking the survey data. The big advantage on this technique is that in case there is a problem the team can exit much faster than entering the cave and no survey data is lost. The survey in technique is a team effort and requires at least two divers. 2) During the survey out technique the line is laid on the way in and the survey is done on the way out resulting in a delayed exit and if the dive needs to be aborted then the survey is ‘hanging’, meaning the survey date is not connected to the starting point. The only advantage of the survey out technique is solo diving situations, with all of their particular advantages and disadvantages.

A cave survey as well has the potential for negative impact onto the cave environment as the dive is very slow and we need to get very close to the survey stations (tie off) as well as the line in terms of potential entanglement or breaking the guideline. Very good buoyancy, trim and propulsion techniques are a must for a cave survey. If a cave map does already exist for a particular cave one should not conduct a resurvey of the cave in order to protect the cave environment. There is no reason to fuck up a cave just to get the survey data and destroy what we love so much.

cave cartography

Once the survey data is collected the data needs to be saved on paper (my favorite) or electronically, or both. Line maps or stick maps can be produced in free software programs such as Compass. The data then can be imported into software programs such as Corel Draw and the map can be produced electronically.

cave cartography

My favorite way of making a cave map is the traditional drawing technique as I see the map as a artistically expression of the cave surveyor and cartographer. The first step is to draw a working map with all the cave information drawn onto milimetric paper. The second step is to draw a copy onto onion paper with all the cave information drawn onto the paper. The third step is to print out all the information shown on a cave map such as names, locations, index, scale, symbols and notes. The last step is to go to a copy shop and have your map copied and ready you are to publish your art work. You even can send a copy of your cave map to the NSS-CDS as they do a yearly competition for the most beautiful cave maps.