Paying extra for the Manly Fast Ferry will soon be a thing of the past for regular public transport users as the government tries to shore up a minister's seat.
The privately run service, which currently costs an adult $10.20 for a trip between Circular Quay and Manly, will be included under the $50-a-week Opal cap from mid-2023.
Peak services will also be boosted to six an hour, creating a turn-up-and-go service for those travelling the picturesque route.
"There might be a green (public) one there or a blue (fast ferry) one - it doesn't really matter. They're all going to be part of the same product," Transport for NSW chief executive Howard Collins told reporters on Friday.
"The big winners will be those from western Sydney who have taken the day trip to Manly as an important part of their summers," Transport Minister David Elliott said.
The 15-year contract extension announced on Friday also contains provisions to convert the ferries to hydrogen-diesel hybrids in four to five years, subject to regulatory approvals.
The new fuel mix would use hydrogen as an accelerant, reducing the quantity of diesel needed. The first iteration should cut carbon emissions by 50 per cent, with an aim of an 85-per-cent cut by 2038.
Plans are afoot to eventually provide a fully electric service by 2038.
Mr Elliott thanked officials for burning the midnight oil to complete the deal with the service's operator, NRMA.
It's the fourth announcement in as many weeks for local member, Environment Minister James Griffin, who faces a challenge from Climate 200-backed teal independent Joeline Hackman.
Mr Griffin sidestepped a question on whether the new discount was an attempt to curry favour but said the fast ferry sitting outside the Opal fare system had been raised by voters for "many, many years".
"What we're seeing is people wanting more reliability, more frequency to get to and from Manly and this .. does exactly that," he told reporters.
"It will deliver a great outcome for the environment and help us get on our way to net-zero emissions that this government is proudly pursuing."
The deal to pull the fast ferry under the cap won't result in the government subsidising the NRMA, the government says.
Instead, a "pain-gain" agreement will see both parties sharing funding and profits, depending on commuter numbers.
"Over the 15 years, the predictions are that there will be money flowing back into government and less charge for our customers in overall tax," Mr Collins said.