Near miss from a silent killer


On a picture perfect Sydney summer Sunday, a family of Mum, Dad and three young siblings were out enjoying a day on their wakeboard boat. After a few hours of enjoying towing activities, the boat was making its way back to a boat ramp in Middle Harbour. When passing through a 4 knot zone, the kids decided to sit on the marlin board with their backs against the transom. A short time later, the kids decided to lie on their bellies with their feet trailing in the water.

Soon, the father noticed that his four year old son appeared unconscious with this face in the water. They immediately retrieved the boy, contacted 000 and met an ambulance at the boat ramp. With the application of 100% oxygen therapy at the scene, and later treatment in hospital, the boy made a full recovery. But it was very close.

What happened? The boy suffered from carbon monoxide (CO) poisoning, known on boats a ‘the silent killer.’ The boy’s sister explained later that her brother thought it would be fun to place his face in the exhaust bubbles in the water. He inhaled CO, rendering him unconscious very quickly. Further exposure would have led to death.

CO is a product of combustion of engines, more being produced from petrol engines than diesel engines. CO is odourless, colourless and tasteless. It bonds to our blood’s haemoglobin 240 times faster than oxygen, thus depriving our internal organs of oxygen very quickly. It is deadly.

Lessons Learned:

  1. Never allow anyone to sit on marlin boards or swim platforms whilst a vessel is underway, or even at rest whilst engines are idling.
  2. Never “teak surf”, which is an activity where people hang on to the marlin board and get towed along by a moving boat.
  3. Make sure all compartments of a boat are well ventilated at all times, and be aware of the “caravan effect” (see Safety Report titled ‘Covers could have been a covert killer’).
  4. Be aware of on-board generators – even when a vessel is anchored or moored, generators still produce CO. This is particularly present at or near the swim platforms of houseboats. Never allow people to swim under these platforms.
  5. Be aware of the symptoms – victims will appear bright red, or flushed, and their extremities, such as toes and finger tips will appear bluish in colour. Early symptoms include the victim feeling tired, confused, sluggish, slurry speech.
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