A national transport company will spend $10 million building two ferries to increase sailings for Bruny Island after frustration over long queues and bottlenecks at peak times.

SeaLink Travel Group Limited was awarded the contract to run ferry services for the increasingly popular Bruny Island for the next 10 years.

The company will build two ferries that can hold 36 cars.

The current ferry, the MV Mirambeena, has the capacity for almost twice that number but SeaLink said extra sailings would mean increased capacity under its operation.

SeaLink's Paul Victory said there would be improved frequency, with 20-minute turnarounds between crossings.

"We'll be able to provide improved customer amenity onboard, there'll be passenger lounges onboard and it will provide a fast, efficient operation for the community of Bruny Island and visitors," he said.

SeaLink will take over the service in September and keep operating the government-owned MV Mirambeena as well as one of its other ferries until the new vessels arrive.

The first new ferry is expected to be ready in late 2019, and the second will be delivered in the first half of 2021.

The company will gradually introduce an online booking system for the service between Kettering and the island.

Twenty per cent of ferry capacity will be set aside for passengers who turn up at the terminal on the day.

The MV Mirambeena will be kept in service until a new replacement arrives. ( ABC News: Rhiannon Shine )

Online booking system welcomed

Infrastructure Minister Jeremy Rockliff said the new contract would result in increased crossings.

"As the popularity of Bruny Island has grown, so has the demand on the ferry and that's why the Government's focus has been to provide a service that will best meet the future demands of all users," he said.

SeaLink has not provided a breakdown of fares for visitors to the island yet but prices will be higher in peak times and lower in off-peak times.

Mr Rockliff said the Government would fund discounted fares for Bruny Island residents who pre-booked for the first year of the new service.

"The discount will mean that Bruny Island residents who pre-book will pay $10 per trip rather than the $16 as they do now," he said.

Luke Martin with the Tourism Industry Council of Tasmania welcomed the new operator and the news of an online booking service.

"You know, if you're stuck down the bottom end of the island and you have to be home to catch a flight back into Hobart to leave the island that night, you want to be able to have confidence that you'll be able to book yourself," he said.

"The reality is, those sorts of quaint little quirks of the service that have served the island so well, Tasmania so well, for the past 30 or 40 years are perhaps not what people expect in 2018."

Sealink's second new ferry is expected to start in 2021. ( Supplied: SeaLink )

Opposition questions contract

SeaLink will take over from local operator Bruny Island Ferry Company, which has been running the service for more than 20 years.

Opposition MP David O'Byrne questioned the Government's support for local industry.

"They've given the tender for the Bruny Island ferry to a mainland contractor and they've not mandated that that contractor build the vessels in Tasmania," he said.

"The Government makes the decisions on the conditions of the tender, why didn't they stand up for Tasmanian jobs?"

Mr Rockliff said while it was a commercial decision for SeaLink whether the ferries were built in Tasmania or not, the company had previously built vessels in the state.