Vineyard Sound is the stretch of the Atlantic Ocean which separates the Elizabeth Islands and the southwestern part of Cape Cod from the island of Martha's Vineyard, offshore from the state of Massachusetts in the USA. On its eastern end it connects to Nantucket Sound. Nantucket Sound is a roughly triangular area of the Atlantic Ocean offshore from the U.S. state of Massachusetts. It is 30 miles (48 km) long and 25 miles (40 km) wide, and is enclosed by Cape Cod on the north, Nantucket on the south, and Martha's Vineyard on the west.[1] Between Cape Cod and Martha's Vineyard it is connected to the Vineyard Sound. Ports on Nantucket Sound include Nantucket and Hyannis, Massachusetts.