No, the bats are not white, they go in and out of the caves nightly and sleep fairly close to the openings. There are some blind fish in some of the more remote (from light) parts of the cave system. I'm not a professional cave diver either, I was a dive nut though for many years and have a lot of friends who have been involved in mapping much of the underwater cave system here in the Yucatan. They took me along a bit
although I never went and got the certification. This is Mexico as we say.
They have connected many kilometers of the underground water system here as it flows to either the Caribbean or the Gulf. Lots of that exploration was not something I would do, really extreme diving. Lots of very small spaces where they had to remove their tanks to get through. Also there are enormous spaces that are the size of indoor football stadiums. It is a very inspiring thing to swim through these huge spaces with stalactites and stalagmites hundreds of feet high that have been there for milleniums. I have seen paintings on the walls and the remains of cooking fires in areas that have been underwater since the last ice age. Due to the limestone, the water is perfectly clear so you have the feeling that you are flying effortlessly through air.
My definition of technical diving is when going to the surface is not an option, a lot of this fit that description because the entire cave is underwater. Divers have drowned within 20' of air because it was ahead of them not above them and they couldn't reach it in time. Also, because of the distances, they would have to take extra tanks, leave them in as far as they could go in one trip, go back out, decompress. Then on the next trip they would use a scooter as far as the drop tanks and then continue and do the same thing again... and again and again. Pretty interesting but hard work. They used to dive in shifts 24/7 in some of the more remote areas because the longer they were there the more supplies had to be hauled in (by hand or by horse) and of course daylight was irrelevant.
The ancient Maya considered the caves as the entrance to the underworld and altars and sacrifices were made there. The current Maya also leave altars and offerings just inside the entrances. We would often have them shown to us by the Mayan guys with us. They were usually in a tucked away corner and had flowers and fruit and candles.
The caves (called cenotes here) are the main supply of water on this limestone peninsula with no surface rivers. Until a few years ago our condo on the caribbean coast in Akumal got its water from a cenote about 14 miles inland. This is in a very touristy area. Now we are on "city" water but I'm sure it also comes from wells driven into the underground cave system.
There are theories that a prolonged drought caused many of the cenotes to dry up and that this was a factor in the abandonment of some of the ancient Mayan cities. It's not the only theory and it is probable that there were several factors involved. For one thing, without sufficient water for crops there would be famine, another is that many of the cities reached a population that was unsustainable. The main temples and the homes of the elite were generally in the middle of the most fertile land and as the population grew, the land used for food was less fruitful or depleted. Many of these cities had populations in the hundreds of thousands at their height. It kind of sounds like some current conditions doesn't it?
The Yucatan is a fascinating place and I'm sure any of you would enjoy visiting it. It has a long coastline on both the Caribbean and the Gulf of Mexico, contains 3 states (Yucatan, Campeche and Quintana Roo) and many fascinating Mayan ruins. Milkmood, the food IS delicious and the flora and fauna unique. The music is great too, a mix of Caribbean and Mexican. It's also very safe without some of the problems afflicting other parts of Mexico.
