"It stayed around a good hour or two, then it swam out to sea and disappeared."
Mrs Rayner said lots of tourists had flocked to see the whale.
"Some people thought it could have been rubbing barnacles off on the rocks.
"It was really quite entertaining."
She said there were often other types of whales visiting but it was unusual to see a sperm whale.
They had seen other wildlife like humpback whales and dolphins in the area before.
"We get orcas off and on quite regularly, they come in quite close ... we've got a couple of sea elephants at the moment."
There were also plenty of seals and their pups around the coast, she said.
"The wild life here is quite impressive."
Sperm whales normally prefer deep water and are usually found offshore and in areas with submarine canyons, such as Kaikoura, where they're present all year round.
An adult can reach sizes of 11-18m in length.
