Hi, my brother drowned while diving alone in 3.5 metres of water in a river beside his boat, he had planned to clean the hull after tying lines under the hull. He was alone just as many of you agree is ok. He apparently had borrowed gear for the task and his not diving buddy was stationed on the boat to pass down lines. It seems he may have had a coughing fit for whatever reason, perhaps the underwater asthma attack whilst vertical, bugs in his reg, no one knows. He surfaced after kicking furiously with out his reg in his mouth yelled for help, became unconscious then sunk. Now his buddy was not a diver, let alone a trained first aider had no idea how to help, jumped in the water but as you would imagine was unable to find my brother. It took the police divers and aerial wing 1.5 hours to find his body in the murky water. Do the water police think its okay to dive alone? Clearly not. My brother had open water, advanced open water, rescue diver, and some other specialty tickets and of course he thought it would be okay to dive alone in 3.5 metres to undertake a simple task that he probably had done before many times. He had not dived for a few years due to finances and his tank was past certification. Is it ok to dive alone? Depends if you are happy to expect the unexpected and die as a consequence of complacency! Have a great dive and live long.