Mike Daniell was an experienced spear fisherman.
Mike Daniell was an experienced spear fisherman.

How Mike's tragic death may save other young lives

BIG-hearted Sunshine Coast spearfisherman and builder Mike Daniell was well known among family and friends for pushing his limits.

He enjoyed living life to the full, excelling in next frontier, whether it be fishing, diving, surfing or wake boarding.

No-one really knows yet exactly the circumstances around his tragic death while spearfishing off Mudjimba Island on Saturday. One theory, though is he suffered a shallow water blackout.

It's caused by a loss of consciousness under water caused by a lack of oxygen to the brain. It comes about after holding your breath for too long. The most common cause is voluntary hyperventilating.

Divers without scuba gear dangerously take rapid breaths before their descent.

The practice removes the normal 'breakpoint' defence in our body - the undeniable urge to breathe.

According to experts, there are two chemical sensors in the body.

These detect levels of oxygen and of carbon dioxide (CO2 ) in the blood. These protect us from a lack of oxygen. The CO2 sensor is the most sensitive; and when CO2 rises to a critical point the breakpoint is reached first.

Normally, when a swimmer is trying to stay underwater for as long as possible, the "breakpoint" forces the swimmer to surface and take a breath.

If a person is submerged and the "breakpoint" is reached whilst the mouth and nose are still underwater, the irresistible urge to take a breath occurs, and water is inhaled into the lungs.

Sunshine Coast fisherman, surfer and big hearted builder Mike Daniell.
Sunshine Coast fisherman, surfer and big hearted builder Mike Daniell.

But if the swimmer or diver "blows off" too much carbon dioxide before submerging, it will take longer for the carbon dioxide sensor to force the "breakpoint".

The result is the person may lose consciousness underwater.

According to the Royal Life Saving Society of Australia, every year several Australians drown from shallow water blackout due to hyperventilating before they submerge.

"Drownings have been recorded whilst free diving in the ocean; and at public pools where people train for sports such as underwater hockey,'' advice from the society says.

"There are recorded cases of children or young people hyperventilating or trying to swim long distances underwater and then drowning, even in home swimming pools."

Royal Life Saving urges parents to warn their children against the practice.

"Shallow Water Blackout is extremely dangerous. Medical science has not yet established how many breaths it is safe to take prior to attempting endurance underwater swimming."

To be clear, we don't know what caused Mike's death. Shallow water blackout can also be caused by heart abnormalities and other factors.

But let's hope Mike Daniell's story helps sparks greater awareness of these risks, particularly among younger, less experienced divers.