Ticket prices for Portland’s Casco Bay Lines are set to increase again in June.

Ben Dinsmore, the general manager of the ferry service, confirmed Friday that round-trip, peak season adult tickets will increase from $14 to $16, while 30-day passes will rise from $48 to $51. Annual passes are slated to go from $432 to $435.

The Casco Bay Island Transit District’s board of directors approved the change at a meeting Thursday, Dinsmore said.

The decision marks the ferry service’s second passenger-ticket price increase in the past three years. In 2024, the service approved its first rate hike in 15 years, with round-trip ticket prices increasing 82%.

Last year, the board also greenlighted a price hike for the vehicle ferry to Peaks Island.

The board was originally considering a $3 increase to single-ticket sales. Dinsmore said the board chose a $2 increase for now, with the intention of potentially raising prices by another dollar next year.

He said the transit district’s operating deficit has grown substantially because the ferry service hadn’t raised rates for so long prior to 2024.

“We’re trying to balance affordability for island residents with the fact that we run a $3.6 million operating loss,” Dinsmore said Friday.

The rate change is subject to approval from the Maine Public Utilities Commission, which affirmed the 2024 increase.

Casco Bay Lines services Peaks Island, Little Diamond Island, Great Diamond Island, Long Island, Chebeague Island and Cliff Island, with peak season running from April 18 to Oct. 12.