On 3 January 1927, Gibbs was out driving a launch at Port Hacking when he noticed Mervyn Allum struggling in the water. Thinking the youth was drowning, Gibbs made his way to the nose of the launch in order to give assistance to Allum. It was then that Gibbs realised Allum was being attacked by a shark, and he immediately dived into the water.
Gibbs
Allum