The desperate search for a 20-year-old Melbourne man has entered its second night after he disappeared beneath the surf at a notorious Mornington Peninsula beach.
The North Melbourne man, who is on holidays with his dad and younger brother, was swimming with his sibling when they got into trouble near Gunnamatta Beach before 7pm on Friday.
Their dad swam out to help the brothers before he also started to struggle.
Surf lifesavers managed to rescue the father and his 16-year-old son.
Despite having a hold of the older brother, he slipped away.
"The two people that were rescued were very, very fortunate lifesavers had been called to another incident nearby," Emergency Management Commissioner Andrew Crisp said.
"(The beach) wasn't patrolled."
The father and son were taken to hospital and have since been discharged.
A wide-scale search for the 20-year-old was launched, which spanned from Rye Back Beach to Cape Schanck.
Gunnamatta Beach was closed for much of the day as the police air wing circled the skies, as the search took place from in the air and on the water, with green dye dropped in to the ocean to track currents and tides.
Gunnamatta is a notorious beach and conditions can change in a matter of moments.
"Conditions like yesterday when we had a strong easterly wind with a lot of water movement and high tide, it just creates a dangerous environment unfortunately," Life Saving Victoria Peter McDonell said.
The search for the 20-year-old will resume at first light on Sunday.