‘R.I.P beautiful boy’: Tributes flow for teenager who drowned in Melbourne lake

Touching tributes been laid beside a Melbourne lake where a popular teenager and another man died after a drunken night swim turned to tragedy.

Haydyn Gibbons, 19, and another man in his 30s, died after they got into trouble while swimming in a lake on Redleap Reserve at Mill Park last night.

A large floral tribute, with a bottle of beer and a can of whiskey and dry ginger, was left on a small pier next to the lake, a message written on a bollard in black texta.

It read: "To our little brother Haydyn, may you rest in peace beautiful boy. We love you always, forever young'.

Friend Chelsea Ruby Nesci said Mr Gibbons he had been living with her family for the past four years.

"Nobody could prepare me for what has unfolded tonight," Ms Nesci wrote on Facebook yesterday.

"Never did I think I'd be coming home to your empty bedroom - I'm sitting here wide awake, still in shock that you're no longer with us."

Witnesses were heard screaming for more people to help last night, including one man who jumped into the water and began frantically searching for his friends.

Neighbour Nathan Henderson said he heard the panicked calls, and helped police try to save the men.

"A police officer arrived and jumped in. So I sprinted home, grabbed a surfboard so we had something to float on... and then we started searching the lake," Mr Henderson told 9NEWS.

"(One of their friends) was just rolling on the floor, crying, and just devastated."

Three police officers who arrived first on the scene spent 15 minutes in the water trying to find the pair before a full-scale search began.

The bodies of the men were pulled from the water around 10pm.

Senior Sergeant Mark Smith said the men were affected by alcohol.

"Unfortunately because of the effects of alcohol, two of them have got into trouble while swimming across the lake," he said at the scene.