I have become greatly concerned that sport divers have been looting cenotes. Is there any governmental organization on a local or national level involved in systematically protecting such historically valuable sites?

Kristin: Looting of cenote sites is a big concern for the Mexican authorities. This is what Memo wrote in a recent email:

INAH [the Instituto Nacional de Antropologia e Historia, Mexico's federal anthropology and history institute] is the government agency in charge of this and INAH is making a huge effort to watch the cenotes, but there are non-governmental efforts as well, and here pubic universities are playing an important role by educating students to be guides and guardians of the cenotes as part of the one year social service that every student in Mexico must perform in order to pay back the government for their free education.

Local communities also play an important role in protecting their cenotes from looters. On several of the sites we dove, we had to check in with the head of the local ejido, or community. His house was often at the base of the road that led to important cenotes, and he had the authority to check our vehicle for artifacts when we finished diving. Memo told me a great story about a time when an ejido leader caught a diver driving back from a cenote with a Spanish-era vessel in his car. When the diver refused to return the vessel to the cenote, the villagers ran to the church and rang the bells to summon the police. The diver was arrested, and the vessel today is in the local museum.

Still, the ultimate responsibility lies with the divers. If objects keep disappearing from these sites, then no one will have the incredible experience of diving them in the future.

How many years experience do you need to dive cenotes? I understand it is far different from open water diving like lakes and oceans being they are inclosed underwater caves basically. What other diving experience do you need? How dangerous is this type of diving?

Kristin: There are several different types of cenotes--some are more like small ponds or lakes and have very little overhead obstruction, while others have very restricted openings. The general consensus within the diving community is that diving in more open cenotes--those where you are always within sight of the sinkhole entrance--is appropriate for divers who have cavern diving certification or equivalent experience. Divers who hold an advanced open water certification are eligible for cavern certification.

Unlike cavern diving, full-blown cave-diving is a technical specialty that requires special equipment and rigorous training and enables divers to penetrate hundreds--even thousands--of feet deep into underwater cave systems.

Memo and his cave-diving certified students aren't going to find themselves 500 feet back in a narrow cave restriction, since artifacts are not going to be found that far away from the entrance of a cenote. But what Memo does occasionally blur the line between cavern- and cave-diving. Some cenotes are very dark or much more cave-like, with low ceilings and narrow passages, than others. This is where the safety training and equipment of cave-diving--reels, high-intensity lights with backups, double tanks--come in handy.

The most dangerous part of cenote diving is obviously the fact that you're diving in an overhead environment and may not be able to immediately surface in case of an emergency.

In Yucatan, there are cenotes for divers with various levels of skill. You just have to be certified, competent, and not claustrophobic.

It seems the wide dispersal of pyramids, villages, and cities left by the civilizations throughout Mexico would be overwhelming for an organization like INAH. Do they have any help from other government organizations to help them with this almost impossible task of protecting sites from looters?

Memo: Yes, it is an overwhelming task but fortunately we can now count on the support of a number of government and non government organizations to support the work of watching Mexico's cultural patrimony. However, it is the civil society the one that can more effectively assist INAH in protecting sites. We are creating brigades of university students, and especially the villagers that live nearby the settlements and cenotes, they are the ones that can really help keep the sites free of looting, because they have the understanding that these places are their inheritance from their ancestors. I think that this huge task will be simplified if we can make the locals involved and conscious of the fact that this wonderful patrimony belongs to humanity but especially belongs to them.

Once you go down into the cenote and go to the bottom are there any tunnels that lead to dry ground and air that a person could survive? Or is it just an enclosed water hole?

Memo: The cenotes are complete cave systems that were formed thousands of years ago. During the last glaciation they got flooded, but due to their karstic nature they are complicated labyrinths. That is why in a few cases, there is air bubbles within this systems. A person could eventually survive if this air bubble is ventilated via communication with the exterior but this is seldom the case. Most of the flooded cave systems lack this kind of air or "dry" areas.

What does it take to become an archaeologist?

Kristin: Take a look at these links:

www.digonsite.com/drdig/archaeologists/31.html

www.salary.com/careers/layouthtmls/crel_display_Cat10_Ser198_Par296.html

www.sha.org/sha_kbro.htm