Panic While Scuba Diving: Warning Signs, Triggers and What to Do

How common is panic in scuba diving?

Common, in every survey that has asked. In a 2000 survey of 12,231 recreational divers by David Colvard, M.D., and Lynn Colvard, 24% of men and 37% of women reported at least one panic episode while diving. A 1986 survey of 245 divers by William Morgan found higher figures when near-panic was included: 50% of men and 64% of women. DAN's medical guidance sums up the research the same way: more than half of divers report at least one episode of panic or near-panic.

Morgan's 1995 review found general agreement that panic lies behind many diving injuries and deaths. Entry-level training reflects this: ISO 24801-2, the standard behind open water courses, requires students to know the causes, symptoms, prevention and management of mental stress, panic and overconfidence. Related articles are in our safety guides.

What role does panic play in diving accidents?

A large one, mainly through what panic makes a diver do. The instinctive response to a threat is flight, and underwater flight means a fast ascent. Laura Walton, a clinical psychologist and dive instructor, describes the behaviours of panic as incompatible with the constraints of scuba. Morgan's group wrote that panic appears to be the primary stimulus for rapid ascents.

The data below come from different kinds of study, so the numbers are not directly comparable. Read together, they place panic next to running out of gas and rapid ascents as one of the three mechanisms that turn a problem into an injury. For how these fit with overall death rates, see is scuba diving dangerous?.

Early signs of panic in yourself

Breathing is often the first thing to change. The US Navy Diving Manual notes that fear can trigger involuntary hyperventilation, and that divers using scuba for the first few times are likely to hyperventilate to some extent because of anxiety. A slight smothering sensation from breathing resistance can start the same pattern, and cold water adds to the urge to breathe faster.

Overbreathing brings its own symptoms: dizziness, tingling in the hands and feet, and a feeling of air hunger even when you are breathing more than enough. That last one feeds the fear. DAN's guidance describes what follows: attention narrows, and the diver loses the ability to sort out options.

Walton describes panic as the end point of a build-up of stress. The useful signs are the ones before that point: breathing faster than the effort explains, fixing on one thing, rushing a task, or a strong urge to go up. Breathlessness can also have a medical cause, such as immersion pulmonary oedema (see the questions below).

Warning signs in your buddy

Watch before the dive as well as during it. DAN's list of pre-dive signs: unusually talkative or unusually quiet, avoiding certain subjects, checking gear compulsively, asking the same questions again. DAN notes that many uncomfortable divers get in anyway because of ego or not wanting to hold others up, so keep the conversation going and don't push a hesitant diver.

In the water, DAN lists struggling with equipment, wrong or confused signals, sudden loss of buoyancy control and rapid breathing as early signs; wide eyes, a spat-out regulator and failure to communicate come later. SSI adds a quieter form, sometimes called passive panic: a diver who seems calm, stares blankly and sinks or drops the regulator without calling for help.

Early help can be small. DAN's examples are reseating a hose that has come loose or handing over a backup second stage. The aim is to solve the problem before it grows.

Stop, breathe, think, act: how it works

It buys time. DAN's reasoning is that stopping to breathe and think gives an uncomfortable diver a window to solve the problem and to relax before the discomfort becomes panic. BSAC's safe diving guide says the same in fewer words: if you find yourself breathing hard, stop (after signalling your buddy) and regain control. The wording varies. PADI's low-visibility advice is to stop, breathe, stay calm and communicate with your buddy instead of swimming around blindly.

The breathing step has a physiological basis. The Navy's treatment for involuntary hyperventilation is to relax and slow the breathing rate. It also warns that after hard work, the feeling of breathlessness can persist or even increase for a short time after you stop. Stay still and keep slowing your breathing rather than bolting for the surface.

• Stop: stop swimming, get stable in the water and signal your buddy.
• Breathe: slow, full breaths with long exhalations. Keep the regulator in your mouth and don't hold your breath.
• Think: name the problem. Is it gas, the mask, cold, your buddy, the current? What are your options?
• Act: fix the problem, or move shallower, or end the dive with a normal ascent. DAN's advice for discomfort that won't settle is to go shallower or end the dive.

Common triggers and how to train them out

Name your trigger, then practise it where failure costs nothing. That is DAN's advice: if clearing your mask is the bane of your existence, practise it in a pool until it no longer scares you. The triggers below come up again and again in agency and DAN material.

• Mask flooding. In a DAN field study of 840 dives, mask flooded or dislodged (including panic) was reported 17 times, and ISO 24801-2 requires mask removal and breathing without a mask in every entry-level course. PADI's first step needs no dive at all: mask off, snorkel in, eyes closed, face in a bowl of water, breathing only through the mouth. In the water, settle your breathing before you flood the mask, then keep the rhythm.
• Air hunger. Hard finning, skip breathing and breathing resistance all push up carbon dioxide, and the Navy lists shortness of breath and a sense of suffocation among the symptoms. Slow down before you are breathless, and see our SAC guide for why skip breathing backfires.
• Gas and regulator problems. In Colvard's survey, about 40% of men and 33% of women had experienced a regulator leak or free-flow, and 40% of men and 27% of women had been low on or out of air. Practise air sharing, and plan a reserve with our gas planner, so neither situation is new when it happens.
• Low visibility. PADI's advice is to agree signals and separation procedures before the dive, use a buddy line if you might lose sight of each other, and abort the dive if you become separated or disoriented.
• Claustrophobia in gear. DAN notes that claustrophobia may surface only under stress or in poor visibility. PADI's advice is to tell your instructor about the fear, including feeling constrained by your gear, and to face it in small, graded steps.

Why avoiding the trigger makes it worse

Because avoidance teaches your brain the threat was real. DAN's guidance on phobias puts it plainly: avoiding situations that provoke anxiety worsens the phobia over time. Walton describes the same loop in divers: each restriction feels better for a moment, the next bout of discomfort triggers more avoidance, and the range of dives that feel safe keeps shrinking. She recommends planned pauses, for example a few minutes looking at the sea between the buddy check and the entry, or set stops on the descent, so stress is noticed and let go before it builds.

Treatment follows the same logic. For a diver with post-traumatic symptoms after an out-of-air incident, Colvard describes cognitive behavioural therapy with diaphragmatic breathing and progressive exposure, sometimes done in the water. Be wary of quick fixes: Morgan's review found that studies of hypnosis, imagery, meditation and relaxation in anxious divers had not produced consistent results.

When to talk to a doctor or an instructor

Talk to a doctor before diving if you have been treated for panic attacks or another psychological condition in the last five years. That is question 7 on the Diver Medical Participant Questionnaire, the screening form for recreational dive courses published through UHMS, and a yes to its follow-up questions means a medical evaluation is required before the course. BSAC is specific for its members: a history of panic attacks, or continuing medication for anxiety, needs specialist advice from a UK Diving Medical Committee referee before training starts.

A diagnosis does not decide the answer on its own: the questionnaire sends you to a doctor, and the doctor judges your case. DAN asks divers to disclose conditions and medications to their instructor and agency, and treats drugs that carry warnings about driving or operating machinery as risky for diving too.

Talk to an instructor about the trigger itself: what exactly frightens you, and a plan to practise it. After a bad incident, get help if nightmares, flashbacks or dread about the next dive persist. Colvard describes a diver with nightmares and flashbacks after about 25 seconds without air, and says such symptoms warrant help whether or not the diver returns to diving.