Mystic — More than 2½ years after its last cruise, the steamboat Sabino will resume taking passengers on tours of the Mystic River on Wednesday.

The trips follow Mystic Seaport’s approximately $1 million restoration of the National Historic Landmark, which has the distinction of being the oldest coal-fired steamboat in regular operation in the United States.

The 109-year-old ship, which can carry up to 74 passengers, has been an iconic sight on the river for decades and at one time featured a Dixieland band.

“It’s such a joy to have her back. This boat is just the heartbeat of the museum,” David Childs, the Sabino’s captain, said Tuesday afternoon. “It gives people a chance to step back in time to a slower way of life.”

“It’s just an honor to drive this boat,” he added.

The 57-foot-long Sabino was built in 1908 in East Boothbay, Maine, and spent most of its career ferrying passengers and cargo between Maine towns and islands. Its engine, which is powered by a coal-fired boiler, was built by the J.H. Paine & Son Co. of Noank. The boat came to the Seaport in 1973 and was designated a National Historic Landmark in 1992.

The boat’s last passenger cruise until now was on Columbus Day 2014. Later that year it was hauled out of the water and the restoration work began in the museum shipyard.

The work included reframing much of the stern, replacing some of the planking and decking and parts of the superstructure. New benches were installed for passengers. The biggest part of the project was the fabrication of a new boiler, based on a design from the 19th century, to power the engine. The work is expected to keep the boat in service for the next 25 to 30 years.

“That’s why we needed to do this work. It sets her up for a good long run now,” Seaport spokesman Dan McFadden said.

The work was funded with a mix of state and federal grants and private donations. Since the work was done, the boat had sailed three times — once from the museum shipyard to its berth, once to lead the recent Antique and Classic Boat Rendezvous parade and once for its Coast Guard inspection to carry passengers.

“It a symbol of the museum that extends beyond the museum to the community and the state. Having her back on the river is being welcomed by everyone here,” said Chris Gasiorek, the museum’s vice president for watercraft preservation and programs.

He said the boat offers visitors not only a chance to see the museum from the water but to experience how people of the 19th and early 20th centuries traveled.

“It’s different than arriving by I-95. People generally arrived here by sea. Being able to give people that experience is really important,” Gasiorek said.

He and other Seaport officials described people along the river waving and cheering the boat when it led the antique boat parade two weeks ago.

“It seems everyone has a Sabino story. They went on it with their spouse, or the person who would become their spouse, their kids, their grandchildren. It tells us something about the role she has in this community,” McFadden added.

Other than Childs, who has logged 12 years as its captain, the person who may know the Sabino best is its chief engineer, Jason Cabral.

“It’s nice to get her fired up again,” he said.

Cabral, who is in charge of the engine and the new boiler, said he is still figuring out the effects the wind, tides and amount of coal have on the boiler.

“Every boiler makes its own types of noises,” said Cabral, whose job it is to learn what all those noises mean. “They’re all different.”

He and Childs work as a team communicating via a system of bells. Cabral said he has to make sure the fire is hot enough so there’s power when Childs needs it and not too hot when the boat gets back to the dock.

Sabino operates every day except Tuesday through Oct. 9. There are three cruises a day: a 30-minute upriver cruise for $8 per person at 2:30 p.m., a 90-minute downriver cruise to the mouth of the Mystic River for $18 per person at 3:30 p.m., and a two-hour downriver cruise at 5:30 p.m. for $25 per person. There is also a two-hour downriver cruise at 11:30 a.m. on Sundays for $25 per person.

Museum admission is not required for downriver cruises but is required for the 30-minute cruise. Children 3 and under are free, but they must have a ticket to board. Tickets can be purchased up to two weeks in advance by calling (860) 572-5331. Sabino also is available for group charters.

j.wojtas@theday.com