The largest cruise ship of the season stopped in Portland Harbor on Sunday, sending its thousands of passengers into the streets and creating a festive atmosphere along Commercial Street. The massive, 1,141-foot-long vessel – the Anthem of the Seas – dominated the harbor. When viewed from the Casco Bay Bridge, the ship obscured much of the city’s waterfront from its berth at the Ocean Gateway, where it was to be docked for nine hours before departing at 5 p.m.