The condition of three victims of a boat explosion north of Sydney has improved but another person remains fighting for life.
Eight people suffered burns and smoke inhalation in the explosion at Brooklyn near Dangar Island on Sunday afternoon.
A man and two women on board who were taken to Royal North Shore Hospital in a critical condition were downgraded to a serious but stable condition on Monday.
Another woman taken to the same hospital remains in a critical condition.
Two people taken to Westmead Hospital in a serious condition, are now stable in Concord Hospital.
The vessel sank in shallow water with a slow fuel leak, with hazardous materials experts called in to contain it.
The cause of the fire is under investigation.
© AAP 2021