The undersea earthquake which shook Tonga is more than 3700km from mainland Australia's east coast.
Yet so significant was the eruption that the ripple effect did indeed hit Australian shores.
Sea level gauges returned date on the wave heights generated by the tsunami and, of the Australian data, the impact on Norfolk Island was most significant.
The wave amplitude there was measured at 1.27m at 9pm Saturday.
The Gold Coast, Southport Jetty, Port Kembla, Twofold Bay, Battery point, Burnie and Rosslyn Bay all recorded sub-1m impacts.
The Australian Government Bureau of Meteorology issued tsunami and marine warning alerts on Saturday. They were downgraded on Sunday but warnings to remain alert remain.
Beaches have been closed up and down the NSW coast on Sunday.
A NSW SES spokesman on Sunday asked for people not to enter the water.
"Marine threats tsunamis can generate dangerous swells and conditions, so as a precaution we're asking people not to go into the water," the spokesman said.
The wave heights recorded across the Pacific after the undersea earthquake
- Source: Australian Bureau of Meteorology