A teenager who suffered serious injuries after being attacked by a shark while spearfishing off the Northern Territory coast was due to have further surgery overnight as medical staff work to save his arm.
Sean Whitcombe, 17, was diving around 40km offshore of Nhulunbuy in the Gulf of Carpentaria when the attack occurred on Sunday morning.
Medical staff believe Whitcombe will likely survive and keep his injured arm but he was in a critical condition on Monday night following emergency surgery.
Mr Whitcombe told medical staff he had been mobbed by numerous sharks when he was airlifted 1000km from Nhulunbuy to Darwin.
He was in about five metres of water and is believed to have been bitten on his arm and leg while coming to the surface after spearing a fish.
The main injuries were significant bites to his upper left arm that damaged blood vessels and could easily have killed him, given how much blood he lost.
His friends including an Aboriginal trainee nurse have been hailed as heroes after administering first aid by wrapping clothes and towels around him as a tourniquet to reduce the profuse bleeding and trying to keep him calm.
Top End Health surgical executive director Mahiban Thomas said he was confident Mr Whitcombe would survive and keep his arm but it was too early to tell what permanent damage there was.
"That is a very lucky young man who was exceptionally well supported by his friends who are to be commended for excellent work keeping him conscious and keeping his blood loss down," Dr Thomas told reporters.
"He certainly would've died if both the emergency response, intermediate response and final reaction from Royal Darwin Hospital had not been as polished as it was."