Thwaites, Andrew John

44y · Male·Carbon monoxide toxicity causing loss of consciousness and fatal drowning

A 44-year-old experienced recreational scuba diver, Andrew Thwaites, died during a dive on 10 August 2016 at Cherubs Cave, Moreton Bay, Queensland. He inhaled compressed air containing dangerously high levels of carbon monoxide (2,366 ppm compared to safe limit of 5 ppm), which caused loss of consciousness underwater and drowning. The air was filled at an amateur dive club's compressor that was poorly maintained by well-intentioned but unqualified volunteers. The compressor lacked proper maintenance records, temperature monitoring, and air quality testing. It had suffered overheating with evidence of lubricating oil ignition, causing carbon monoxide production. Critical lessons include: all breathing air compressors must comply with Australian Standards 3848 and 2299; regular air quality testing is essential; maintenance must be performed by competent persons using manufacturer guidelines; compressors require carbon monoxide detection systems; and divers should routinely test filled cylinders before use.