Unexplained Panic Can Kill a Diver

We've all been in a situation underwater where we might have been on the verge of panic. I know I have. When something goes wrong during a dive, a cool head will enable you to identify the problem and do something about it.

I've been nipped on the hand by a lemon shark; been lost at night inside the Umbria, a wreck I thought I was familiar with; lost my weights deep inside the Vandenberg; and had all manner of other equipment malfunctions at depth in my days as the technical editor of Diver Magazine. The truth is that, while you have an adequate air supply, you have time to figure things out.

For that reason, I made it a habit to make routine dives with two independent tanks, each with its own separate regulator.

But when your air supply is inexplicably cut, the only solution is to make it to the surface, and exactly that presaged my entry into the world of diving journalism. Even so, I still managed to ascend fairly slowly, exhaling all the way.

Panic Deaths

This past January in the UK, officials held an inquest into the death of a 68-year-old experienced diver who made a rapid ascent while diving the wreck of a former East German minesweeper in Malta in 2024. Only three minutes into the dive, Darrel Pascoe made an uncontrolled ascent and died, having suffered a pulmonary barotrauma (lung over-expansion injury). No one knows why, but he obviously must have held his breath as he shot upwards.

Pascoe had not dived for 18 months and had not provided a medical certificate from his doctor confirming fitness to dive, though it is a statutory requirement for all divers in Malta.

On December 30, Nathan Scott, a 50-year-old Australian businessman, died while diving 500 yards off Tulamben, Bali. Another saw him, for no apparent reason, appear to panic and then make a rapid ascent from only 50 feet. In the process, he abandoned his regulator.

The second diver followed the panicking diver, a senior executive of Dubai-based Tristar, and found him unconscious at the surface. He was bundled into a passing fishing boat and rushed to shore, but was unable to be revived. An autopsy will not clarify matters since drowning and SIPE show similar quantities of water in the lungs.

SIPE Can Cause Panic

Many divers drown when they still have plenty of air available. Until only a few years ago, it was attributed to panic or even nitrogen narcosis, but nowadays the more likely cause is submersion-induced pulmonary edema (SIPE), which happens when fluid leaks from the bloodstream into air sacs in the lungs. It can lead to heart failure or other cardiac problems. The immediate effect is the inability to inhale. Some divers discard their regulators in the mistaken belief that they were not providing air, when in fact it was their lungs that had difficulty inhaling.

The only solution for a diver suffering from SIPE is to get them out of the hydrostatic pressure of the water as quickly as possible.

Whether one can prevent SIPE is unclear. But a few predisposing factors may be drinking too much fluid before a dive, pre-existing cardio or respiratory conditions, overexertion during a dive, tight wetsuits, stress during a dive, and older age.

According to Douglas Ebersole, a cardiologist in Lakeland, FL, and a technical dive instructor who consults for DAN, it is not depth-related, and it often occurs in healthy individuals in shallow water. He says SIPE can be difficult to diagnose and is most likely underreported because many other conditions present similarly, such as saltwater aspiration syndrome, pulmonary decompression sickness, and respiratory infections. Symptoms include believing a regulator isn't working properly or believing you are out of air. Both might cause panic -- understandably so -- and cause divers to remove their regulators. (Dead firefighters are occasionally found with their breathing devices removed, and they are not SIPE victims.)

Panic Otherwise

There may have been some other reason to cause panic -- a sting from a marine organism such as a hydroid or a bite -- but certified divers rarely panic when in benign conditions and not very deep.

Divers who panic underwater are unable to reason clearly and cannot consciously control their actions. It's a physiological and psychological state that can occur when a person is -- or perceives themselves to be -- under severe stress. They become unable to communicate effectively and (if they survive) are likely unable to have an accurate memory of what happened. So, how to avoid panic?

When things go wrong, a cool head is essential. Inability to see a solution to a problem can result in the brain short-circuiting to fight-or-flight mode, neither of which is helpful in the underwater environment. Nitrogen narcosis can cause unease that might lead to panic. The answer is to reduce your depth. Hypercapnia, or the inability to fully exhale carbon dioxide, the byproduct of metabolism, can be caused by shallow breathing and will cause distress. People with a (non-clinical) history of panic are more likely to use avoidance strategies when facing emotionally distressing situations.

I've dived at Cape Kri where, just as you're planning to finish a dive at 20 feet, you get whisked down to 120 feet on an unexpected down current before being returned to the surface. If you dive within your capabilities and give yourself sufficient slack, carrying more breathing gas than you think you need, you can put unplanned-for events like that down to experience.

John Bantin

To learn more about SIPE and learn how you may be susceptible, read about it in our October issue: https://tinyurl.com/mry4u6dk