A sick crew member on a 94m American icebreaker 222km off Northland's shore had to be winched off ship by helicopter.
Northland Rescue Helicopter pilot Dean Voelkerling said they were notified late on Saturday of a man on the United States ship Nathaniel B. Palmer - tasked with extended scientific missions in the Antarctic - who was sick and needed to be transported to hospital.
The man had abdominal pains.
"I understand the ship was transiting between Sydney and Tahiti. When it became evident he needed to be evacuated they turned around and headed back towards New Zealand for evacuation," Mr Voelkerling said.
About 9am on Sunday Northland Rescue Helicopter and a St John paramedic flew 120 nautical miles (222km) off shore to the ship and the man, who was in a stable condition, was winched into the helicopter to be transported to Whangarei Hospital.
Mr Voelkerling said it was "a little bit windy" with 20 knot winds and 3m to 4m swells.
"It was a big, stabilised boat so it was reasonably straightforward.
"It was very comfortable to go and do. It was no different to flying between here and Hamilton and back."
Mr Voelkerling said they arrived at Whangarei Hospital about 11am.
A Maritime New Zealand spokesman said usually the patient's health insurance footed the transfer bill.
Soon after arriving at Whangarei Hospital, Northland Rescue Helicopter flew to Kaitaia Hospital to transport a sick child to Whangarei Hospital for further treatment.
Last week was unusual for the rescue helicopter, with 16 missions including one paediatric intensive care unit transfer, two neonatal intensive care unit transfers and two extracorporeal membrane oxygenation transfers.
The latter is a technique of providing prolonged cardiac and respiratory support to people whose heart and lungs are unable to work properly.
Patients were transferred from Whangarei, Tauranga, Rotorua and Hamilton to Auckland City Hospital.