SeaLink’s glistening new ferry Wanggami that cost more than $57 million to construct alongside sister boat Ruwi has been officially launched during a VIP ceremony at Port Adelaide.

While it is several months late – and Ruwi is yet to arrive – the gala launch marks a milestone in upgrading the vital service to Kangaroo Island for tourism, freight and general passenger traffic.

SeaLink general manager Tracy Croft said Ruwi was expected to arrive either late next month or early September from the shipyard in Batam, Indonesia, a voyage of 5200 nautical miles.

Ms Croft said the sister ferries are both expected to meet their projected launch date of September 23.

She said the new ferries combined $57 million construction bill represented the largest investment in the service’s history and is expected to deliver significant improvements in capacity, reliability and customer experience.

Kangaroo Island regional tourism manager Megan Harvie said the ferries would be a “game changer” for both locals and tourists.

The launch day featured the tradition of christening the ship by the smashing of a champagne bottle on the hull performed by non-executive director of SeaLink operator company Kelsian Fiona Hele, a smoking ceremony from Ngarrindjeri man Mark Koolmatrie and a blessing from Father David Still of St Paul’s Church Port Adelaide.

The two ferries were named for the Ngarrindjeri words Wanggami meaning “kangaroo” and Ruwi meaning “land”, Mr Koolmatrie said.

The ferry upgrade means a three day halt to services as maintenance work is done on docks at Cape Jervis and Penneshaw, as part of a five week transition before the existing ferries are decommissioned.

SeaLink acting chief operating officer Phil Boyle said the shutdown was scheduled between September 1 and 3.

Asked whether the new ferries would change the fares for travellers, Mr Boyle confirmed ticket prices would remain the same.

Mr Boyle also said the old ferries would be phased out and sold once the two sisters were operating.

He said Batam in Indonesia was chosen as the construction site of the ferries due to “three main reasons: capacity, capability and cost”.

The ferries feature a dedicated pet lounge and other luxuries for travellers, including a design that means passengers will no longer have to reverse their cars onto the ferry and can instead drive forwards on and off the boat.

The new ferries also have features like a passenger lift to all three decks, a larger cafe and improved seating options.

When the service commences, during peak season (September to April), SeaLink will operate 22 departures (11 trips each way) Monday to Friday, and 18 departures (nine each way) on Saturday to Sunday.

Off-peak season (May to August) will operate 14 departures a day (seven each way) every day.

Significantly larger and identical in their design, the new ferries can carry substantially more vehicles per departure, with eight vehicle lanes and approximately 150m of extra vehicle lane length per departure.