A ferry in Penobscot Bay carrying vehicles and passengers from Islesboro to Lincolnville in this BDN file photo.

Outraged Islesboro residents have sued the state’s ferry service for doubling the costs of tickets to and from the mainland.

The lawsuit filed Wednesday in Kennebec County Superior Court argues that the Maine Department of Transportation “improperly, unfairly, arbitrarily, wrongfully and unconstitutionally [raised] ferry rates to the point that many long-term island residents and businesses can no longer afford to live or do business on Islesboro.”

The suit asks the court to reverse the fare hike, claiming it constitutes “an illegal taxation without representation.”

The lawsuit lists “inhabitants of the town of Islesboro” as the plaintiff, naming four specifically, including Gabriel Pendleton, a town selectman and owner of Pendleton Yacht Yard. Pendleton claims in the suit that the new rate will increase the cost of getting materials from the mainland and make it harder to compete with mainland boat yards.

Philip Seymour, an Islesboro retiree listed in the lawsuit, said he spent $1,330 on ferry fares last year getting to the mainland for doctor’s appointments and grocery runs. That same number of trips would cost him $2,900 under the new rates, he said.

Paul Hatch Jr., an island contractor who regularly has to send large trucks on the ferry, said in the lawsuit that the new rate could force him to lay off workers or close his business entirely.

Islesboro town officials declined to comment Wednesday.

The ferry service’s new rate structure, which was announced last month and went into effect on Monday, caused an uproar on Islesboro. The state decided on a flat rate across the system — $11 for a round-trip ticket, or $30 for anyone with a car.

The Maine State Ferry Service, under the umbrella of the Maine Department of Transportation, runs ferries between mainland docks and the islands of North Haven, Vinalhaven, Islesboro, Matinicus, Swan’s Island and Frenchboro.

Previously, each island had its own rate, and rates for tickets purchased on island were discounted with the goal of saving residents’ money. The state says that system was overcomplicated, and the discount was abused by people who didn’t live on island.

An adult resident on Islesboro who once paid $5.50 for a ferry ticket now pays nearly double. If they have a car, that cost increases from $13.75 to $30. Islesboro residents argue their rate should be less than other islands because their ferry trip is the shortest and most heavily used, accounting for the bulk of ferry service rides.

The rate changes have met little resistance on other islands, which are seeing their fares stay relatively steady or drop significantly under the flat rate. The cost of taking personal vehicles from Vinalhaven, North Haven and Swans Island dropped from $49.50 to $30 for non-residents, while locals saw their vehicle fares increase by $2.75.

Matinicus, the most remote of the islands, saw its round-trip fare drop from $33 to $11. The cost of bringing a car dropped from $86 to $30.

The ferry service hadn’t increased its rates since 2009, and said it needed to raise fares to avoid a projected operating budget shortfall in 2020.

There’s been little disagreement over the need for an increase, but the yearlong debate over how best to go about it has been contentious.

In November 2017, the state was considering a structure in which it set a rate for Maine residents and a higher rate for people from out of state. In March, the state delayed its plans to move to that system after some islanders expressed concerns that it was unfair to seasonal residents. A month later, it proposed the flat rate, taking Islesboro residents by surprise.

Islesboro’s lawsuit claims that the state didn’t follow proper process because the structure it ultimately chose didn’t match any of the proposals discussed at public hearings over the past year.

State officials say the former system held the ferry service back from using new technology, such as online sales and improved data collection. Ferry service officials argue the use of technology and flat rate will improve customer service across the system.

Maine taxpayers pay about half the operating costs of the ferry service through taxes, the rest is generated through fares and fees.

A message sent to the state ferry service Wednesday afternoon wasn’t immediately returned.

Follow Nick McCrea on Twitter at @nmccrea213.

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