Key Points:

A 93-year-old woman has died on board a New Zealand polar ship that was retracing the path of her father on the Scott expedition.

The month-long voyage had been Barbara Johns' lifelong dream as her father, Edward Nelson, was a biologist on the Terra Nova expedition from 1910 to 1913 with British Royal Navy officer Robert Falcon Scott.

Mrs Johns fell in her cabin during rough seas south of Macquarie Island on Tuesday and died from head injuries. Her son Andrew, aged in his 60s, was with her.

The vessel, Spirit of Enderby, is retracing the steps of Scott, Ernest Shackleton and other great explorers of the Ross Sea region.

The expedition, In the Footsteps of Scott and Shackleton, journeys to the subantarctic Snares, Auckland, Campbell and Macquarie Islands visiting five historic huts.

Leader Rodney Russ, from Heritage Expeditions, said the ship's doctor treated Mrs Johns and spoke by satellite phone to specialists at Christchurch Hospital but she did not regain consciousness.

Mrs Johns and her son, who has remained on the expedition, had made the trip to New Zealand from their home in Spain to join the voyage.

"Barbara was on a special pilgrimage," Mr Russ said. "It was her lifelong ambition to see where [her father] had lived and worked and to visit the hut where he was based in Antarctica."

Since the beginning of the trip from Bluff last week, Mrs Johns had made friends with most of the other 50 passengers, 24 crew and 12 staff, Mr Russ said.

"They were amazed at the energy, determination and sheer tenacity of this woman. She was small in stature but large in life. She participated in landings at the Auckland Islands and Macquarie Island and enjoyed the wildlife, especially the penguins.

"[We] are proud to have been able to help Barbara to achieve her dreams," Mr Russ said.

"We are immensely saddened by her death and our thoughts and prayers are with her family and friends."

The expedition is continuing and when members reach Scott's hut today, they
will observe a moment's silence for Mrs Johns.

Her body will stay on the ship until the expedition returns on March 10.

Maritime New Zealand spokeswoman Sophie Hazelhurst said that because the ship was Russian-flagged - it has been leased by the New Zealand expedition company for 15 years - it would be up to Russian authorities to launch an inquiry into the death.

The New Zealand authorities might be called to investigate when the ship is next in port, under the direction of Russian officials.