It was pure luck that Associate Professor Ian Ferguson was on Coogee Beach when shark attack victim Leah Stewart was pulled from the water on 13 June.

It was a typical Sydney day and the emergency physician and retrieval specialist was enjoying a coffee with his children when a four-metre-long great white shark attacked the 35-year-old primary school teacher close to shore.

Her injuries were horrendous — the shark had all but ripped off her left arm and savaged her left thigh.

Her right hand had also been sliced open and the tendons detached as she punched the shark as it tried to pull her under.