Parents of a seven-year-old boy rescued after six hours in the sea off Queensland have hailed his "fighting spirit".
Julian Hohnen is in a stable condition after being plucked from the sea with his dad and a friend off the Sunshine Coast on Sunday after a boat sank.
His father Maike Hohnen, 38, and family friend Stephen Jeacocke, 48, clung to debris from the 5.2 metre vessel while taking turns keeping the boy afloat.
They were winched out by helicopter about 2.30am, with Julian taken to hospital in a critical condition suffering hypothermia.
He remains in Queensland Children's Hospital in Brisbane while Mr Hohnen and Mr Jeacocke have been released.
Authorities said the trio were lucky to be alive and the Hohnen family are lauding Julian's improvement.
"Our son has improved significantly today (Monday) and is now in a stable condition and talking to us," his parents said in a statement.
"This is a testament to his fighting spirit.
"He still requires further assessment, but his improvement today has given us hope."
A major rescue operation was launched before dawn on Sunday, after a distress call from the vessel which had begun taking on water 14km off the coast.
The crew of an anchored tanker spotted the trio and helped guide authorities to their location.
The rescue operation for Julian was fraught with danger because winching a patient with hypothermia can cause their body temperature to drop further, a Queensland ambulance spokeswoman said.
On social media prior to the incident, Mr Hohnen described his "beautiful son" as someone who puts a smile on his face every day.
© AAP 2019