Trapped by Depths: Guido’s Fatal Dive Into Diepolder #2
| Incident Location | Diver Full Name (deceased) |
|---|---|
| United States — Sand Hill Boy Scout Camp, Florida — Diepolder #2 | Guido |
Just under a decade later, 29-year-old Guido traveled from his home in Italy in the spring of 1999 to witness the immense depth of Diepolder #2 for himself. By that year, entering and touring Diepolder #2 required meeting a rigorous list of qualifications.
Entry Requirements
- Divers needed proof of completing cave dives in at least five other systems.
- They were required to have a minimum of 100 logged cave dives.
- Specialized diving gear, diving tanks, and mixed-gas equipment were mandatory.
Guido met every requirement and looked forward to the long journey to Florida. He also planned to write a magazine article documenting his adventure upon his return to Italy.
The Allure of Diepolder #2
The cave was famed not only for its depth and demanding environment but also for its water clarity, often described as “gin clear.” Guido brought his camera to capture the scenery.
On April 26th, he arrived at the Sand Hill Boy Scout Camp with his travel partner, Simone. They would be guided by Sandra—an expert diver with extensive experience at Diepolder #2.
Preparation
At 5:00 p.m., the group completed the required paperwork before suiting up. Their diving suits, diving masks, mixed-gas cylinders, and other equipment were essential for the extreme depths they planned to reach.
The Dive Begins
Descent to the Depths
Their dive plan called for reaching depths close to 300 feet. At such depths, breathing surface air is dangerous due to nitrogen narcosis. Advanced divers counter this by using gas mixtures with reduced nitrogen once they exceed 100 feet, or 30.5 meters.
Fully equipped, the divers slipped beneath the water and began their descent. They dropped through a 180-foot narrow vertical shaft, navigating it with precision before reaching the Junction Room. From there, they headed toward the highlight of the dive: the colossal chamber known as the Ballroom.
Inside the Ballroom
Some sources describe the Ballroom as nearly the size of a basketball arena. Cave divers prize it for its vast space, striking beauty, and abundant marine life. Its crystal-clear waters create a sensation akin to drifting through outer space.
Guido was mesmerized. The three divers rose toward the ceiling of the chamber and slowly followed its perimeter. Guido photographed continuously until they reached the entrance of the room again. With the exploration complete, they began their return toward the Junction Room and the narrow passage leading out of the cave.
The Ascent and Decompression
Decompression Planning
Because of the depth and duration of the dive, the return trip required multiple decompression stops. A diving computer on each diver’s wrist calculated how many stops were necessary and how long each stop should be.
During ascent, divers switch breathing gases as needed. This is why they often stash different mixtures along the route. They may even carry a bottle of pure oxygen, which shortens decompression time—but such oxygen can only be safely used at 20 feet (6 meters) or shallower.
Critical Mistake
Carrying the Oxygen Tank Too Deep
Tragically, Guido made a fatal error. A pure oxygen tank was attached to his set of diving cylinders, which should have been placed at a shallow decompression stop. Instead, he carried it through the entire dive.
At the 120-foot decompression stop, Guido removed one regulator and replaced it with another. He took a deep breath from the new regulator.
Immediate Consequences
He instantly began convulsing uncontrollably. Simone and Sandra rushed toward him, but they could not assist. The breath he inhaled came from the pure oxygen tank, which was highly toxic at that depth.
Oxygen Toxicity Underwater
Two Types of Oxygen Toxicity
- Pulmonary Oxygen Toxicity
- Central Nervous System (CNS) Oxygen Toxicity — sudden and deadly.
Guido suffered CNS toxicity. The moment he inhaled the high-oxygen mix at depth, it severely impaired his brain and spinal cord, triggering a violent seizure.
Underwater seizures are extremely dangerous. When Guido convulsed, the regulator from the pure oxygen tank was expelled from his mouth. His jaw locked shut, preventing Simone and Sandra from replacing it with the correct regulator.
Final Moments
When CNS oxygen toxicity strikes, the only chance of survival is to reach the surface immediately, regardless of decompression risks. Simone and Sandra tried to bring Guido up, but his limp body made the ascent impossible. They were forced to leave him inside the cave.
Upon surfacing, they alerted authorities. Later that night, recovery divers brought Guido’s body to the surface. Dive experts believe he likely died the moment he inhaled the pure oxygen at depth—his central nervous system essentially shut down.
Guido’s death could have been prevented had he stashed his pure oxygen tank at the proper shallow depth on the way into Diepolder #2.
