The requirements are for all passengers over 12 years old and come into effect on December 15.
Those showing a negative test result would need to have been tested within 72 hours of travel.
"We've adopted the same policy used by Air New Zealand for their domestic flights so passengers can have a consistent travel experience, regardless of whether they travel by sea or air,' Interislander general manager Walter Rushbrook said.
"Our ferry passengers already have to show their booking number and ID at check in at Wellington and Picton, so we hope to minimise any delays by asking for Covid-related travel information at the same time," Rushbrook said.
"Our staff will be on hand at the terminals to scan passengers' My Vaccine Pass information either off their phones or from a printed pass.
"We'll confirm negative test results either by viewing a text message from a Covid test provider or letter from a medical practitioner."
The booking system would be upgraded to integrate vaccine and test status and charging stations would be at terminals in case phone batteries were low, Rushbrook said.
Interislander staff are required to have had their first dose of a Covid-19 vaccine by December 11 and the second by January 17.
Any staff not double-vaccinated by December 15 will need take a Covid-19 test every 72 hours and wear protective equipment.
Full refunds were available for anyone wanting to cancel because of the new rules. There would be no charge for anyone re-booking because of a Covid-19 test.
