Premier Mark McGowan and Tourism Minister Paul Papalia today announced there would be an additional ferry service offered to Rottnest Island visitors from November this year.

Captain Cook Cruises will be running the service from the island's busiest ferry port - Fremantle.

The Rottnest Island Authority is always looking for ways to improve access to Rottnest Island and encourage business competition that benefits visitors.

A total of 645,000 people visited Rottnest Island in 2016-17, a six per cent increase in visitation from the previous year.

The State Government hopes the new ferry service will help build on those numbers.

Captain Cook Cruises will join Rottnest Express and Rottnest Fast Ferries in providing ferry services for visitors to the island.

Comments attributed to Premier Mark McGowan:

"This new ferry service gives visitors more opportunities to experience the island, which is great news for the local businesses.

"There will not only be 20 new jobs created to operate the ferry service, but there will also be a multiplier effect with the creation of jobs on the island as businesses continue to grow from increased visitation.

"We hope the additional service will put downward pressure on the price of a trip to Rottnest, making it more affordable, particularly for families and tourists who wish to enjoy a holiday on the island."

Comments attributed to Tourism Minister Paul Papalia:

"If we want to keep increasing visitation numbers, it is necessary to increase accessibility and services to the island.

"The more people that visit Rottnest Island, the more dollars spent in local businesses both on the island and the surrounding ports.

"We need to ensure Rottnest Island remains competitive, relevant and continues to be a must-visit tourism destination."