Commanding officer of HMNZS Wellington Lieutenant-commander Matt Kaio, of the Bay of Islands, said he hoped the Royal New Zealand Navy ship would leave for the Ross Sea about noon.
But the departure was weather-dependent and could be delayed by a "big low-pressure system".
The patrol season was scheduled for three weeks.
A day in the Southern Ocean had 21 hours of sunlight, he said.
Ministry for Primary Industries officers would be on board to conduct compliance checks of fishing vessels.
"It’s the navy’s job to get them there safely."
"It is one of the most beautiful places on this earth ... it’s pristine and untouched."
The chance to sail in the Ross Sea was a privilege and it was special to wake to a 10,000-year-old iceberg floating past, he said.
The crew had been preparing for nearly two months "to go to the Ice", including six weeks’ "on water" training.
"We are finally there and everyone is like ‘let’s just go’."
The crew hoped to be back in New Zealand for the closing ceremony of the navy’s 75th birthday celebration on December 18.
Defence Minister Gerry Brownlee said New Zealand was working closely with international partners to "stamp out illegal fishing".
"We have been conducting maritime surveillance in the Southern Ocean using ships since the late 1990s, and offshore patrol vessel HMNZS Wellington is fully prepared for work in these extremely challenging waters."
A Royal New Zealand Air Force Orion surveillance aircraft would also be deployed, Mr Brownlee said.
