A Newcastle teenager is fighting for his life in a Bali hospital after almost drowning in a concrete sewerage drain after a motorbike accident.

Key points: A Newcastle teenager in Bali for Schoolies crashed his scooter into a drain

A Newcastle teenager in Bali for Schoolies crashed his scooter into a drain He remains unconscious in hospital with a severe head injury

He remains unconscious in hospital with a severe head injury A crowdfunding campaign has been set up to help cover his mounting medical bills

Lawson Rankin, 18, was holidaying in Bali to celebrate the end of the Higher School Certificate.

He had recently graduated from St Francis Xavier's College and, like many other young Australians, was with a group of friends for Schoolies celebrations.

On the night of Saturday November 30, Lawson was riding with friends on scooters when one of his friends, who was a passenger, had his phone snatched out of his hand.

Lawson sped up to try to catch the thief and a short time later Lawson's friends noticed his scooter lodged deep inside a concrete drain.

His friends shone a light into the drain and found Lawson unconscious, his helmet split, face down, drowning in the drain.

The helmet 18-year-old Lawson Rankin was wearing at the time he crashed a scooter in Bali on November 30, 2019. ( Supplied: Rankin family. )

Parents praise 'heroic' friends

They pulled him out, performing CPR before locals called an ambulance.

Lawson remains in a critical condition in hospital, with a brain haemorrhage, 20 stitches in his head and an infection from the water that got into his lungs.

In a statement Lawson's family has praised the actions of his friends.

"We are eternally grateful for the heroic actions of these young men," they said.

"This is the most devastating thing a parent can go through, to see our beautiful son in this state in a foreign country is extremely horrific.

"We need to bring him home."

Despite having travel insurance, Lawson did not hold an international licence required to ride a motorbike and that means he is not covered for medical expenses.

Medical bills mounting

A crowdfunding campaign has been established with medical bills already at $30,000.

Just over $100,000 has already been raised.

Lawson Rankin remains in ICU in a Bali hospital after crashing his scooter while on a Schoolies trip. ( Supplied: Rankin family )

"The bills are already over $30,000 for a few days in an international hospital and he may not be able to travel for weeks, so this will continue to rise," the family said.

"Once there is a clearance to get him on a plane, it's expected a medivac flight to Sydney and transfers to Newcastle could be more than $100,000.

"Once home, Lawson is likely to have a long journey of rehabilitation also."

Student coordinator at St Francis Xavier High School Kim Scully said Lawson's friends, who were with him at the time, were devastated but the school was rallying behind them.

"We've got an end-of-year mass this morning and certainly Lawson will be mentioned and thought of there," she said.

"The boys are devastated.

"The two boys who assisted, resuscitating Lawson, are pretty traumatised.

"I think everyone is standing by quietly, praying, and sending all our love to them."

Lawson's father and brother are already with him in Bali.

His mother Therese was reported to be flying out to be with him on Friday.