Filtheyo Island, Maldives. The water around the Maldives seems to be created for snorkelling. Warm, clear water and an abundance of sea life surrounds the tropical islands, while a few hundred feet from shore the reef drops off almost vertically into a blue abyss. These underwater mountain ranges - the natural atolls rising from the ocean floor - provide the perfect arena for free diving.

Floating motionless above the reef, watching a cinema of colourful aquatic life swim by, I allow myself to completely relax and breathe slowly, deeply, deliberately. The purpose of ventilation, or “packing air”, before a free dive is to fill the entire storage area of the lungs and other air spaces with energy for the dive.

Consciously resisting all movement I drift past the outer edge of the atoll until I am completely detached from the safety of the life-giving reef, accompanied by only the sound of my own methodical breathing in the snorkel, peering into the bottomless blue. A wave washes over me. But this is no creation of the ocean’s. This wave is trepidation.

Alone in the ocean, in the knowledge of what I am about to attempt, it is difficult to remain composed.

I take one last, long breath and then jack-knife, head down, one leg extending straight up toward the sky. For an instant I am half in air, half in water - the interface of the two worlds splitting me across the middle - before slipping silently from the surface into the aquatic underworld.

Descent: 0 to 30 feet: The thrust from that initial pull of gravity injects me into the pressurized ocean like a syringe, and then gravity is gone. Four gentle kicks add to the downward momentum. I am very buoyant near the surface and use up more energy in the first 20 feet than I will for the rest of the descent. I swallow and tilt my head slowly from side to side to equalize, left then right. A white-tipped reef shark barely notices me as I pass through 25 feet and equalize again. Reaching toward the deepest blue I tuck my head between my outstretched arms and visualize my body as a frictionless needle accelerating toward the ocean floor.

Beneath is nothing … only infinite indigo. The feeling of dread is, literally, breathtaking.

Descent: 30 to 60 feet: Closing my eyes to focus on the sensation of water sliding past my skin, I make only occasional, low-amplitude kicks to maintain downward momentum.

Equalise. Equalise again.

The hairs on my arms and the rapidly increasing pressure building in my ears tell me I am accelerating. As I feel my chest pulse I try not to wonder how long I’ve been under and consciously avoid looking at my depth meter. I have a long way to go. Relax and stay calm. Conserve energy.

Free diving to between 30 and 60 feet is adventurous. It’s common to pass scuba divers at these depths. A diver will be under the surface for at least a minute, most likely experiencing the initial symptoms of the Mammalian Dive Reflex*. (*See epilogue).
 
Descent: 60 to 90 feet: Gliding through 60 feet I enter a new state of awareness. The litres of air I greedily swallowed at surface have been compressed to zero volume and I am now sliding deeper under my own weight. No more kicking; just glide downward and monitor my senses. To pass out now would not be not wise - an unconscious free diver is negatively buoyant at 70ft and will sink like a rock.

In severe cases of lung squeeze, blood literally bursts from the pulmonary capillaries through the alveoli and into the lungs (air embolism, or pneumothorax). In this situation, free divers literally drown in their own blood. Further increases in depth will cause compression fractures of the ribs as the chest cavity caves in from excessive external pressure.

Descent: beyond 90 feet: Going past the 90-foot mark depends on one thing: how much do I need to save for the return trip? I am now more than a minute from the surface and sinking fast. I remain motionless and streamlined. I make an effort to relax all the muscles in my face and chest, and just listen to my heartbeat. Pressures are great. It is dark. My chest convulses once more but I manage to suppress panic.

In order to conserve energy the heart rate of a deep diver slows dramatically (bradycardia) and the blood vessels in the extremities fully constrict to shut off blood supply to the hands, feet, and eventually the arms and legs (vasoconstriction). Blood is pumped only to the most critical areas of the body – the brain and vital organs (preferential shunting). Insufficient air remains in the chest cavity to equalize pressure, so the lungs are flooded with an incompressible fluid – blood plasma – to prevent total collapse (thoracic filling).

Total depth: 100.6 feet (30.6m): I see only vast emptiness through the blue-black water. This is much like floating in outer space, I expect. My chest feels strangely warm and my fingers and toes all tingly.

Now I am deep. Being here, not breathing or even wearing a tank, is quite awesome. The pressure and apnea have forced my metabolism perilously low, but for a few moments I am fantastically lucid. There is something pure and exhilarating about venturing this far out of man’s habitat, this far back into the origins of evolution …

Suddenly a flood of overwhelming loneliness engulfs me. I just want to be back on the beach with my wife and daughter. I feel my eyes widen and blood drain from my face and recognize I am in the initial stages of panic.

Raw fear grips me as the sound of my dive watch warning alarm pierces the water - indicating I have surpassed 100 feet.

Ascent: a long way home: Instinctively my head whips up and back, mouth agape, eyes searching desperately for the light of day. Abandoning the disciplined, flowing movements I had practiced to conserve energy, I arch my back and thrust violently for the surface.

It is now, kicking furiously to overcome the negative buoyancy while succumbing to the asphyxia-induced chest pulsing, that I fully realize the magnitude of what I have done. I cannot see the friendly ripple of waves on the surface, only blue in all directions, but somehow the air-breathing man in me knows the shortest path to his world. I stretch my fingers straight up, cup my hands and take one long, powerful stroke.

Arms now trailing limply by my sides I rely solely on my legs for propulsion. My thighs start to burn as lactic acid seizes the muscles and almost immediately they start to tremble and lose power. I still have 80 feet to go and I am oxygen deficient. An unyielding desire to walk the earth again is all that keeps me from giving in to a cloak of blackness.

Ascent: the last atmosphere: I now understand why they say drowning is a peaceful way to die. As I battle oxygen starvation and unconsciousness during ascent, the panic fades and I begin to accept the consequences of my predicament. I even smile inwardly.

Then, seeing the surface far above, something is triggered deep within the darkest recesses of my mind: not today. I will not die today. It is this notion – this instinct – that enables me to refocus my senses on getting home safely. As the first ripples of wind on the water’s surface come into view (air!) I leave my body to its own devices and concentrate on just one thing: awareness. I do not want to blackout now.

During ascent a free diver must slow down in the last atmosphere of pressure (30 feet) to avoid the risk of shallow water blackout. As the lungs re-expand the sudden drop in pressure can cause oxygen to quite literally be sucked out of the blood.

Resurfacing: Breaking the surface I am overcome not by elation, but relief. It is behind me. I live. I will breathe again.

My first gasp at the atmosphere is not to intake air, but to expel a mixture of blood and carbon dioxide. This triggers a coughing fit, making my first breaths of air somewhat less pleasurable than I had anticipated. Luckily I am able to stay afloat and breathe between coughs, as the blood drains away from my lungs and back into my arms and legs.

In competitive free diving the validity of an attempt is dependent on the physically integrity of the athlete during and after the dive. Competitors must recover unassisted for the attempt to count. This means no "samba" (loss of motor control) or "blackout" (loss of control over one’s own airway).

Exhausted, and not quite sure how badly damaged I am, I head for shore. Not even when I emerge on the beach, bloody and spluttering, do I feel truly safe.

A new personal best. On that balmy Tuesday morning in the Maldives I dived to a depth of 100.4 feet – on just one breath. It took 2 minutes and 2 seconds. I stopped coughing blood after two hours, but I had a headache for two days. The third day I suffered vomiting and diarrhoea and spent in bed. Perhaps by body was trying to tell me something.

Although my attempt was not witnessed and endorsed by the international judges of IFDA, my dive watch was calibrated for seawater and I satisfied IFDA rules by resurfacing conscious and in control of my motor skills.
I was completely alone out there. I did it neither for glory nor recognition, but to satisfy an intrigue.