I am planning a similar trip...
Hi Gary,I have just completed my plans to to do a similar trip, starting in Salem, MA to Provincetown (tip of the cape) to Marion, Cuttyhunk, Block Is., Martha's Vinyard, Nantucket, etc.... For trip planning purposes I bought the following charts -132461321813237You may need a more detailed map around Newport, RI. I always have a MapTech chartkit for places such as this.As others have mentioned the currents in this area can be strong so you will need a copy of Eldridge - Tide and Pilot Book 2006 ($12.95).For planning purposes I have found "A Cruising Guide to Narragansett Bay and The South Coast of Massachusetts" to be essential. You can find both books at West Marine (http://www.westmarine.com) or Amazon (http://www.amazon.com) or if you get stuck contact the folks at my local shop, FL Woods (http://www.flwoods.com) and they will set you up for sure. You should know that to get a mooring or slip in Martha's or Nantucket you need to have reservations *soon*. Many dates are already sold out. See here (http://www.edgartownharbor.com/) for Edgartown, MV and here (http://www.nantucketboatbasin.com) for Nantucket. Don't be discouraged if you do not get a reservation though. Edgartown has some first-come first-served moorings and each place has good safe anchorages. Let me know if you have questions and I will try to help.