A dive in Cenote Zapote, Puerto Morelos, Mexican Yucatan.
A narrow shaft drops straight down from the surface pool to 25m depth, where it abruptly opens up to a huge chamber that must be 60m across, decorated with unique and unexplained bell-shaped formations. There is a thick Hydrogen Sulphide layer below 30m, well-fed by a steady rain of organic matter from the surface.
Filmed with a Sony NEX-5n with 10-18mm lens in a Nauticam housing with Fisheye Neo video lights on- and off-camera.