ISLESBORO — The ferry Margaret Chase Smith, which services Islesboro from Lincolnville, is expected to be in service for another decade or so.

But a grant from the federal government will allow the state Department of Transportation to begin the design for a new ferry well in advance of the Smith’s retirement.

The U.S. Department of Transportation’s Federal Transit Administration awarded the state DOT $1 million last fall. The money is dedicated to designing a new ferry for servicing Islesboro. The Smith, which can carry 250 passengers and 33 cars, has been in service since 1987.

DOT public information officer Ted Talbot said that any new design will address changes in ferry construction and safety codes that are new since 1987.

Ferry service to Maine’s islands is “critical,” Talbot said. “And we recognize that, which is why we constantly keep our fleet as modernized as we can, as accessible as we can. We recognize it’s part of the lifeblood of transportation for those folks. We constantly are looking for suggestions to do things better. We always want that feedback. Maine is unique in a lot of ways, and this is one of the ways we are unique, in our island travelers.”

Although ridership swells during the summer months for Islesboro, as for all Maine islands, it’s too soon to say whether the Smith’s replacement will need to have more passenger capacity. There might be new specifications with regard to vehicle capacity, Talbot said.

Overall, the latest ferry launched into service, the Captain E. Frank Thompson, now serving on the Vinalhaven-to-Rockland run, represents the latest thinking in design, Talbot said.

“The Thompson is probably the vessel of the future,” he said.

The Thompson was the first ferry to be added to the Maine State Ferry Service fleet in 19 years. It was christened in April 2012, in Rockland. Replacing the Governor Curtis, which was built in 1968, the $10.3 million Thompson has greater passenger and vehicle capacity over its predecessor.

The Thompson is also more fuel-efficient than its counterparts along the coast, holding 6,000 gallons of low-sulfur diesel fuel; and it is more convenient and up-to-date in its passenger appointments, having more interior seating, larger restrooms and an elevator.

The Smith was itself the latest iteration of islanders’ need for greater capacity. The first public ferry boat, the Governor Brann, was launched in 1936 and by the following year was deemed too small for the amount of traffic traveling to Islesboro. The ship was lengthened to carry 12 rather than 10 cars. In 1959, the Governor Muskie, which could carry 24 cars, was launched. In 1987, the greater length and breadth of the Smith meant extensive renovations to the ferry docks on Islesboro and Lincolnville.

Other ferry service improvements are underway in Maine, thanks to $2.4 million in federal funding awarded in 2012 to the state DOT Ferry Boat Discretionary Program. These include an award of  $1.2 million to the Casco Bay Island Transit District in Portland to help cover the cost of engineering and construction of a new passenger ferry, the Wabanaki, to replace the Island Romance, which was constructed in 1973.

The Maine State Ferry Service also received $1.2 million to help cover the cost the design and complete construction of a new ferry berthing system, transfer bridge, fender system and pier support at the Frenchboro ferry terminal.