Looking for unknown places to dive, new underwater caves to explore is one hobby and addictions one can have. A call from the distant past when people were gathering in caves to be protected from mother nature. If you are looking in the Swiss cheese-like limestone rock of the Yucatan peninsula in Mexico, you are in one of the prime areas of Underwater cave formation. If you are looking in the State of Yucatan, you will find yourself in an area full of unexplored cenotes and only a few people who are exploring them. The sheer number of over 1700 unexplored but registered cenotes kept by the Ecology Department is mind-boggling and can give one the feeling of running up the hill. A lifetime of exploration is waiting here. The difference between the caves of the State of Quintana Roo and Yucatan is the depth and extensions of these cave systems. The caves in Yucatan are deeper, but less spacious.

While on a cenote scouting trip in the Yucatan, Daniel Dens and I came across a huge, water-filled depression named Sabak-Ha, which in English means turbid water. A surface pool with a diameter of about 100 feet filled with green, uninviting water. A 40-foot drop from ground to water level is typical of this region. The immense size of this sinkhole made it look so deep that I decided to do my first dive on Trimix straight away. A week before my first dive here, Memo de Anda of Cancun did a dive to 180 feet and reported clear water, but no bottom in sight.

On September 25th, I went to a depth of 354 feet. During the descent, the green algae bloom yielded to crystal-clear water below 35 feet. The enormous size of this sinkhole was breath-taking. I felt like an ant in a bathtub. At a depth of 210 feet, I found a hydrogen sulfide layer with 20-25 feet of visibility trapped in the halocline, the interface between freshwater above and brackish salt water below. At 290 feet, the Talus Cone came into view, the breakdown of what was once the ceiling of this enormous dome. At 210 feet, the diameter of this immense hole is about 250 feet across, filled with clear water and circular in shape. At 354 feet, I hit my turnaround pressure and maximum depth and planned bottom time. I tied off the exploration guideline on a rock sticking out from the wall. I could not see the final Bottom and neither the walls that should enclose this cave. My interest in Sabak-Ha was awakening.

On the 16 &17th of November 1998, Kashi de Cleer and I returned to Sabak-Ha to have a closer look into the walls of this sinkhole. Upon our investigation, we came across a horizontal cave passage at a depth of 180-200 feet, which extended 423 feet horizontally into the bedrock. A terminal breakdown halted the exploration. A cloud of millions of little cave shrimps was greeting us at the entrance and further into the cave we found one of the largest population of blind cave fish we have ever seen in a single location and at that depth. We counted 13 blind cave fish while entering the passage with one sweep of the eye and named the passage Blind Cave Fish Cafi.

On the 20th of May, Ronald Rumm and I returned to see what the bottom was doing. We were descending to a depth of 356 feet and found ourselves swimming horizontally on top of a huge breakdown, entering a giant, deep cavern or cave passage into what we named the Black Abyss. I tied the end of our exploration guide line on to the wall which was on our right. Below us was a black void, a tremendous crack that went into the inky darkness and out of sight. In front, we could not see a wall, neither could we see a wall to our left. We felt very small.

On August 16th, we discovered a new cave passage extending 403 feet horizontally into the bedrock, 211 feet deep, on the opposite side of the Blind Cave Fish Cafi passage. The entrance of the cave passage is the shallowest part of the passage is right at the end of the exploration guideline at 186 feet. Here the Passage splits up into two small leads. Near the guideline’s end, explorers established a side passage; it continues, but only side-mount gear allows passage. Close to the cave entrance are two leads that are going off to the left and right, which remain unexplored. Divers named the cave passage Passaje de Sacrificios (Passage of Sacrifices) because they lost a complete stage bottle and regulator after the dive; it now rests on the bottom at an estimated depth of 280–350 feet.