Ms Te Namu said following the initial quake, the pair went down to the hotel lobby.
"We could hear sirens going hard out outside. People were very anxious and crying. It was madness on the street. Neither of us have ever experienced anything like that."
Aftershocks continued throughout the night "big time", she said.
"We felt sick from all that swaying. Even as we stepped on the flight [home], all around the airport you could feel it. It was like 'get us out of here'."
Meanwhile, a Waipu couple camping at Marfell's Beach south of Blenheim and about 200km north of the epicentre, said their 9.5m campervan was "rocking right over".
"I thought the ground had opened up under the back wheels," said the man, who did not want to be named.