THEIR AIR CYLINDERS WERE NOT EMPTY WHEN THEY WERE FOUND: Unusual Pressure Gauge Readings Spark New Questions in Maldives Cave Diving Tragedy

In the confined darkness of an underwater cave system at approximately 50-60 meters (164-197 feet) in Vaavu Atoll, five experienced Italian divers lost their lives on May 14, 2026. What was intended as an exhilarating exploration near Alimatha island aboard the Duke of York liveaboard ended in tragedy. As investigators piece together the final moments, one detail continues to puzzle experts: the divers’ air cylinders still contained significant gas when their bodies were examined. Now, authorities are reportedly zeroing in on an unusual reading from a pressure gauge attached to their breathing system.

This forensic clue has intensified speculation about what went wrong in one of the deadliest single diving incidents in Maldivian history.

The Victims and the Expedition

The group comprised dedicated marine science professionals and enthusiasts:

Monica Montefalcone, 51-52, associate professor of marine ecology at the University of Genoa, known for her research on seagrass and coral ecosystems and television appearances.

Giorgia Sommacal, her 20-23-year-old daughter, a university student.

Muriel Oddenino, a researcher with ties to the University of Genoa.

Federico Gualtieri, a marine biologist and recent graduate.

Gianluca Benedetti, a professional diving instructor from Padua, who also served in operations for the Duke of York.

Four of the five had strong connections to the University of Genoa. The dive took place in Devana Kandu channel, targeting cave-like structures in a renowned but technically demanding area. Surface conditions included strong winds up to 30 mph and a yellow maritime warning, which complicated both the dive and rescue efforts.

Only one body was recovered on the day of the incident, with recovery operations for the others suspended or slowed due to rough seas and the challenges of the deep, confined cave environment.

Cylinders Not Empty: Ruling Out Simple Air Depletion

Forensic examination of the recovered equipment revealed that the primary cylinders (tanks) were not empty. This has largely dismissed the idea of a straightforward “out-of-air” emergency in which the group simply ran out of breathing gas while lost or trapped.

Instead, experts point toward a rapid incapacitating event that prevented the divers from continuing to breathe from their remaining supplies or exiting the overhead environment. In cave diving, where direct ascent to the surface is impossible, any sudden loss of consciousness or disorientation can prove fatal for the entire team.

The Unusual Pressure Gauge Reading

Investigators are now closely examining data from pressure gauges (submersible pressure gauges or SPGs) and integrated dive computers attached to the breathing systems. According to reports circulating from the ongoing probe, an anomalous reading — possibly inconsistent pressure drops, unexpected residual pressures across multiple tanks, or readings that do not align with the logged dive time and depth profile — has drawn particular attention.

Possible interpretations under consideration include:

Rapid or erratic pressure changes suggesting a free-flowing regulator, sudden leak, or equipment malfunction that went unnoticed until too late.

Inconsistent gas consumption across the group, hinting at a shared environmental factor or contaminated fill.

Readings indicative of improper gas mixing or analysis, such as higher-than-expected oxygen partial pressures not fully reflected in consumption rates.

The Duke of York is equipped to provide nitrox (oxygen-enriched air) blends, which are popular for extending bottom times but require meticulous analysis before each dive. At 50-60 meters, even small errors in oxygen percentage can push the partial pressure of oxygen (PPO2) into toxic ranges.

Oxygen Toxicity and Gas Mix Hypotheses

Diving medicine specialists, including pulmonologists commenting on the case, have highlighted oxygen toxicity (CNS hyperoxia) as a strong possibility. Symptoms can include twitching, visual disturbances, irritability, seizures, and sudden unconsciousness — often with minimal prior warning. In a cave, a single seizure can lead to regulator loss, panic, entanglement, or a silt-out that disorients the entire buddy team.

An incorrect gas mix — whether too high in oxygen for the depth or contaminated with hydrocarbons from poor compressor maintenance — could explain both the remaining gas in the cylinders and any anomalous pressure readings. If divers were breathing a blend they believed was safe but was actually unsuitable, the effects would strike simultaneously or in quick succession.

Nitrogen narcosis (“the martini effect”) at these depths could have further impaired judgment, making it harder for the group to recognize and respond to emerging problems.

Environmental and Operational Factors

Vaavu Atoll’s channels are dynamic. Strong surface winds can generate powerful surge and currents that stir sediment near cave entrances, drastically reducing visibility and increasing physical effort. The group’s high level of experience makes the decision to enter the cave under these conditions a point of intense debate in diving communities.

Questions under review include:

Was this a properly planned technical dive with appropriate redundancies (multiple tanks, stage bottles, reels, backup lights)?

Did pre-dive gas analysis occur?

Were weather warnings adequately factored into the go/no-go decision?

What role did the cave’s topography and any fixed lines play?

Investigation and Forensic Focus

Maldivian police, working with Italian authorities, are conducting a thorough examination that includes:

Detailed analysis of all pressure gauges, dive computers, and cylinder contents.

Gas sampling for oxygen percentage, contaminants, and carbon monoxide.

Autopsies to look for physiological signs of oxygen toxicity, drowning, or barotrauma.

Review of boat logs, witness statements from the Duke of York crew, and any available footage.

The Italian Foreign Ministry is providing consular support to the families, many of whom are grieving not only loved ones but colleagues and mentors in the marine science field.

Broader Lessons for the Diving Community

This tragedy underscores fundamental principles of safe diving, especially in overhead environments:

Gas Management and Analysis: Every tank should be tested with an analyzer before use. Assume nothing.

Depth Limits and Training: 50-60 meters in a cave far exceeds recreational limits. Full technical and cave certifications, plus experience with trimix or other advanced mixes, are essential.

Redundancy: Multiple independent breathing systems, lights, and navigation tools are non-negotiable.

Environmental Awareness: Surface conditions directly impact underwater safety. Conservative decision-making saves lives.

Equipment Monitoring: Unusual gauge readings should trigger immediate action — but in a crisis, there may be little time.

The Duke of York caters to technical divers, yet even well-equipped operations cannot eliminate all risks when human factors, equipment, and ocean conditions align unfavorably.

A Passion Cut Short

Monica Montefalcone dedicated her career to understanding and protecting the very marine environments she was exploring. Bringing her daughter Giorgia on the trip represented a shared family passion. The loss of the entire group represents a significant blow to Italy’s marine research community.

As recovery efforts continue and the investigation deepens, the unusual pressure gauge readings may provide critical answers. They could reveal whether a mechanical issue, gas contamination, or a combination of factors turned a calculated adventure into a fatal miscalculation.

The turquoise waters of the Maldives remain a diver’s paradise, but this incident serves as a stark reminder of the unforgiving nature of the underwater world. Even with gas remaining in the tanks, five passionate and experienced explorers did not make it out. The pressure gauge anomaly may ultimately explain why — offering hard-won lessons that could prevent similar tragedies in the future.

The global diving community mourns the victims and awaits the full findings of the investigation. For their families, clarity on those final moments — and what the gauges truly revealed — cannot come soon enough.