"But over recent weeks we have seen rising verbal threats and increasing tension."
In the past month there were three episodes of threatening behaviour towards staff. This was the fourth and most violent, Chapman said.
"This physical attack on one of our employees, who was simply doing her job, was appalling."
The woman needed treatment at A&E but fortunately did not need overnight care, Chapman said.
She was now resting at home and being supported by SeaLink.
SeaLink was providing support to the rest of its Waiheke team, including security services at the terminal.
Police have been contacted and are investigating the incident.
The transport infrastructure upgrades at Kennedy Point were due to be completed in December.
A police spokeswoman said they were speaking to all parties involved and their investigation as ongoing.