The Pit (El Pit) Cenote

The water at the bottom of the wooden stair looks like a modest pond, and there is nothing under it. The guided profile drops down one wall to 30 m, then climbs back in slow circles around a cylinder roughly 10 m across at the top, 35 to 45 minutes from stair to stair. Lights come along, though most of the dive runs in daylight.

The halocline arrives first, at 14 to 16 m. Fresh water sits on sea water that has pushed inland under the limestone, and the shear between the two blurs everything as you pass through it, like looking through liquid glass. The water clears again below. The salt layer is denser, so buoyancy shifts as you cross, and it is slightly warmer than the fresh water above, which catches people out. Seen from underneath rather than crossed, the same boundary reads as a river running along the ceiling.

Around 30 m the dive reaches a floor that is not one. An opaque hydrogen sulphide layer stretches the full width of the shaft, with tree branches standing out of the top of it and an island of collapsed rock and timber somewhere underneath. That layer is the turn, not a feature to enter. Divers who went in during 2025 described it scattered and smeared rather than crisp, so it is not guaranteed to look like the photographs.

Then the ascent, which is the part people remember. Coming back up above the cloud you cross under the overhang to a sloping ceiling near 10 m where the stalactites are, and the light comes at you from an unfamiliar angle: a column of sunlight falling in through the jungle gash, seen from below. Nobody dives this shaft for what lives in it. Scale, water and light are the whole of it.

119.1 m of surveyed depth sits underneath a dive that turns at 30 m.1 That is the deepest known cave passage in Quintana Roo, and both numbers belong on the same page: one of them describes the site and the other describes your dive. Sistema Sac Actun, the cave The Pit opens into, holds 379,569 m of surveyed passage and ranks second in the world among underwater systems, behind Ox Bel Ha under the same coast.2 Depth is the rarer thing here. Quintana Roo's flooded caves run mostly shallower than 20 m, with tunnels between 2 and 15 m in a web under the jungle, and only a handful of places drop past 70.3

The other cenotes along this corridor are dived for their formations and their passages. This one is dived for a column of water. A light beam down the middle, a visible halocline, a sulphide cloud and depth no recreational diver reaches the bottom of, stacked vertically in a single open room. Divers who have done a dozen of them sort the corridor into decorated horizontal caves and vertical sinkholes, and put The Pit firmly among the second kind.

Dan Lins and Kay Wallen came out into the shaft in the mid 1990s, on a long penetration dive from a cenote to the north, while pushing a connection between two of the region's large systems.4 Exploration ran for fifteen years after that: a descending passage to about 100 m and a chamber beyond a boulder collapse, open circuit pushes in 1997, rebreather dives in 2000 that opened two more passages. The last chapter is the deepest. In 2011 a new 180 m passage named Stairway to Heaven was surveyed on a single dive of 11.5 hours.3 None of that water is part of any guided dive.

The cenote has also given up two dated human skeletons, listed among the ten oldest recovered from Quintana Roo's flooded caves: El Pit 1 at 10,290 years and El Pit 2 at 9,121.5 The remains were lifted for study, and what a diver sees today is a scatter of small burnt bone that looks like an old hearth. Skeletons this old are the reason the archaeological rules here have teeth.

Getting in used to be the hard part. Divers walked about 300 m from the dirt road and lowered gear some 7 m to the water on ropes until the wooden steps were built in the winter of 2012, with the road and car park finished the year after.4 The land belongs to the Ejido Jacinto Pat, which is why the cenote carries Cenote Jacinto Pat as a second name.4

The Pit cannot be your first cenote dive. It sits at Level 3 on the regional register, which wants an Advanced Open Water card or a Deep Diver specialty plus one Level 1 and one Level 2 cenote dive already logged, a minimum age of 15, a dive within the last six months and four divers to a guide.6 The card is the half people remember and the two prior cenote dives are the half that gets forgotten, so plan the trip around it: a shallow cenote first, this one second or third.

A registered guide is mandatory, and the rule is the landowner's rather than the country's. Mexico's federal standard for dive operators has no cave or cavern provision anywhere in it, and one clause lets an advanced diver sign a waiver and dive unsupervised.7 What holds here is the gate and the regional standard behind it. Only a full cave certification removes the guide; a cavern card does not.

There is no permanent line in this shaft. You follow the guide, not a line, and divers are blunt about what that means: these are trust me dives, chosen on the strength of the guide rather than the gear. The other axis is depth. Buoyancy forgives more here than in a low decorated passage, because there is no ceiling to hit for most of the dive, and it forgives less on the way up, where an uncontrolled ascent from 30 m in open water is the real risk.

Practical things, in the order you meet them. The stairway down is steep, narrow and often wet, and a cenote worker lowers and raises cylinders on a line because there is no room to carry them down, so bring tip money. Large cameras cost extra at the gate and compacts do not. Swimming and snorkelling are not allowed in this cenote at all, so a non diving companion has nothing to do here. A 5 mm full suit is the rental default and it is not overkill for 40 minutes at 25 C with a slow ascent. Gates open at 08:00 and close at 17:00, and no dive may start after 15:00, which is a harder stop than it sounds when the drive in takes 6 km of dirt road.