You can take a Nantucket Ferry from Hyannis, MA on the Steamship Authority or Hy-Line Cruises, or from Harwich, MA on Freedom Cruise Line.
Many folks think about visiting Nantucket if they are already visiting Cape Cod or are visiting Martha's Vineyard. The three destinations are relatively close to each other and are all spectacular spots for a family vacation.
If you are already on Martha's Vineyard and are looking for ferry service to Nantucket, those services exist as well but the info below is for ferries from Cape Cod to Nantucket.
The ferry to Nantucket will take about 1 - 2 hours depending upon which ferry you take:
Fast Ferry - 1 hour; no vehicles
Car Ferry - 2 hours; make reservations
High Speed Ferry 1 hour; no vehicles
Regular Ferry 1 3/4 hours; no vehicles508-432-8999
Fast Ferry 1 1/4 hours; no vehicles