A solitary buoy in the remote Southern Ocean has recorded a monster wave of 23.8 metres, the largest wave ever measured in the southern hemisphere.

A wave rider buoy moored at Campbell Island off New Zealand's South Island registered the huge wave on Tuesday, according to Tom Durrant, a senior oceanographer at Metocean, part of Meteorological Metservice of New Zealand (MetService).

The biggest wave ever recorded in the southern hemisphere was measured this week off New Zealand. Credit:MetOcean

Since the buoy only registered the first 20 minutes of each three hours, "it's quite possible, even probable, that there were much higher waves during this storm", Dr Durrant said.

It eclipsed the previous record maximum individual 22.03 metres clocked at an Australian buoy south of Tasmania in 2012.