Emergency services are working to get to an injured person on Moturiki (Leisure) Island, off Mount Main Beach.
A St John spokeswoman said one ambulance was called just after 3pm to help a person on a track with moderate injuries.
It was unclear at this stage what the cause of the injuries were.
A Fire and Emergency New Zealand spokesman said two crews were called to assist ambulance.
He said the crews walked from the Mount Maunganui Surf Club to Moturiki Island with a stokes basket to help bring the patient back to shore.
Police were also assisting.