The Woods Hole, Martha's Vineyard and Nantucket Steamship Authority, referred to colloquially as The Steamship Authority or simply the SSA, is the statutory regulatory body for all ferry operations to and from the islands from the Massachusetts mainland, as well as being an operator of ferry service from the mainland Cape Cod to the islands of Martha's Vineyard and Nantucket, and the only ferry operator to carry automobiles to the island. The Authority also operates several freight vessels, thus serving as the main link for shipping any commercial goods to Martha's Vineyard and Nantucket that are not transported by air. - Source: Wikipedia