ROCKLAND — When the new M/V Captain Dinsmore is put into EV-mode, the passenger won't even know that the vessel is on (in the pen, at least), says Bill Geary, director of Multimodal Operations of Maine Department of Transportation. That much quieter vessel signifies a historic transition for MaineDOT as it welcomes its first hybrid electric/diesel ferry into its fleet, with Rockland chosen as the Dinsmore’s home base, and will serve the Vinalhaven route. Passenger service begins Monday, Nov. 9, 2026, marking a new era in technology and innovation.

Along with unveiling a plaque for the vessel’s namesake, Captain Almer Dinsmore, a November 5 commissioning ceremony at the Rockland dock became the official ceremony to put the vessel in service. A Christening ceremony in Rhode Island, which also involved Dinsmore and his family, was done in November 2024.

The Dinsmore will run mostly in hybrid mode, which includes both electricity and diesel. The diesel engines are smaller, less fuel efficient, according to Geary, but the batteries have an electric motor that boosts the vessel’s velocity to the cruising speed necessary to keep the schedule.

Captain Dinsmore, a 26-year pilot of the ferry service, and a 45-year veteran of sailing, is reminded of when steamships first came along. The earliest steamships ran on wood. But, wood ran out at some point in the journey, so vessels still kept their sails. Then there was a transition to coal, then oil. Now, today’s technology keeps its diesel until the newer advancements prove themselves sufficient.

The Rockland terminal underwent an infrastructure implement for the new vessel in order to add plug-in charging cables for the ship to connect to, should employees deem it necessary. However, with the batteries constantly remaining charged in hybrid mode, Geary does not expect much manual charging to be done.

The new vessel is the same size as the "Richard Spear", 154 feet long, and carries upwards of 250 passengers and 23 vehicles.

The cost of the vessel is $21.9 million, of which, $16.6 million came from an FDA grant.

In order to make room in the fleet for the Dinsmore, MaineDOT will be selling one of its oldest vessels, the Henry Lee. 

Dale Doughty, Commissioner of MaineDOT, thanked all employees who worked on the project.

“Implementing new technology to this scale is not an easy task,” said Doughty.

Many sleepless nights came throughout, he said.

Doughty also thanked the 100-plus employees who work for the ferry service.

A former commissioner used to say: “Transportation is the furnace in the basement. No one notices it, no one thinks, about it until it doesn’t work.”

The ferry service, in recent years, is boasting reliability rates very close to 100 percent, said Doughty.

Dinsmore, who worked with the ferry service from 1978 – 2013, could have gone anywhere with his unlimited captain’s license, according to one of his peers. He could have captained any vessel in the world and made three times more money than at home with the Maine State Ferry, and his desired route: Swan’s Island.

Yes, he responded. “But, running ferry boats is fun.”

There’s not much to look at on the open seas of the Atlantic, he said. He’d rather see land.

“It’s good looking land,” he said. “And also, nice looking boats.”

Music to the ears of residents of the six islands that Rockland serves, for whom the ferry is a lifeline, according to Congresswoman Chellie Pingree, who attended the ceremony.

"We all know, if you live on an island, this is our transportation," said Pingree. "It's your vital line to get to the dentist in the morning...or some people commute on the ferry to get to their jobs."

It's there in the night, when stroke symptoms become visible. 

"It's critically important to us," she said.

Reach Sarah Thompson at news@penbaypilot.com