PORTLAND — After waiting nearly 22 months since its keel-laying, Casco Bay Lines officials weren’t going to reschedule the christening of their new ferry for any reason.

So on Thursday afternoon, when schools, businesses and government buildings across the state were closed because of what forecasters labeled the biggest snowstorm of the season thus far, the island ferry operators were celebrating their newest vessel as planned.

Father Jeff Monroe, rector of St. Margaret’s Parish in Conway, N.H., blessed the boat as the snow piled up on its decks, pointing out that the blessing tradition goes back to the ancient Phoenicians. Monroe was formerly Portland’s director of ports and transportation.

Then, students from Long Island Elementary School counted down from three and Patrick Flynn, president of Casco Bay Lines’ board, smashed a bottle of champagne over the jackstay at the bow.

The 110-foot-long, 32-foot-wide M/V Wabanaki will have a capacity of just less than 400 passengers, and was constructed by the Rhode Island-based Blount Boats over more than two years.

The vessel replaces the nearly 40-year-old Island Romance, which was also built by Blount, and is described by Casco Bay Lines as being similar in design to the eight-year-old M/V Aucocisco III.

The Island Romance carried about 100 passengers fewer than the new vessel.

The M/V Wabanaki, which was funded by a federal stimulus act grant, was delivered to Portland on Jan. 9, when the ferry service began what it described as several weeks of crew familiarization training and U.S. Coast Guard inspections.

The name “Wabanaki,” which roughly means “dawn land” in reference to the northeastern region in the native Algonquian language, was reportedly chosen from submissions made by students from the Cliff Island and Peaks Island elementary schools.

Casco Bay Lines in September held a groundbreaking on a $2.5 million renovation of its ferry terminal, a project that, when complete, will double the size of the terminal from 3,000 square feet to 6,000 square feet. The work will also move the public waiting area closer to the harbor, where new glasswork will allow passengers to look at the water and boat traffic while they wait for their ferries.

The island ferry service carries almost 1 million passengers each year, nearly double the ridership of 25 years ago, when the current terminal was constructed.