Still in MA?
Regarding Winthrop, I would most often take the bus from Suffolk Downs out of East Boston past Revere Beach and through Winthrop to DI. Three ways to get out there- Suffolk Downs buses, small ferry out of Rowes Wharf, larger ferries out Marina Bay in Quincy- not one of the thousands of construction people(admistrators, staff, or trades) were allowed to drive out. After the first bus ride you knew why.