In 2000, two cave divers from California explored underwater passages within the cave.

He is also an experienced cave diver and a former instructor at the College of Oceaneering.

Besides the beach there are some cenotes which have been explored by prominent cave divers.

Obviously, cave divers would be a narrower field of suspects.

It didn't look at all familiar- not a good thing for a cave diver.

Experienced cave divers only; no tours are offered.

Training: A safe cave diver does not intentionally exceed the boundaries of his/her training.

Lights: Each cave diver must have three independent sources of light.

However, there were very few experienced cave divers and almost no formal classes to handle the surge in interest.

The system was explored by cave divers in 1998 to a distance of 440 metres from the shaft.