Hello Bob,
Thanks for your question about bareboat destinations in the Newport area. We had a week on a great charter boat from NarragansettSailing.com last year and had a great time.
Where to go in part depends on what kind of vacation you're looking to have. We decided to pass on Nantucket in favor of hitting other fine destinations. Ours included:
1) Narragansett Sailing Base to 3rd Beach, Newport (free moorings or anchor--dingy onto nice sandy beach)
2) 3rd Beach to Hadley Harbor, MA (adjacent to Wood's Hole; plan on anchoring, arrive for lunch)
3) Hadley Harbor through Wood's Hole to Edgartown, Martha's Vineyard (mooring reservations available; be sure to time your travel through wood's hole with slack tide, and must be clear weather)
4) Optional 2nd day in Edgartown, ashore. (plenty to do but we particularly enjoyed this tour by jeep:
http://www.thetrustees.org/places-to-visit/cape-cod-islands/cape-pogue.html ).
5) Edgartown to Cuttyhunk. Dinner aboard. Relax.
6) Cuttyhunk to Jamestown, RI (Moorings available--beautiful spot with views at night, great restaurants ashore)
7) Jamestown to Narragansett Sailing base.
That was our week last August, and we had a great time. We 2nd REJackson's recommendation of Narragansett Sailing--reasonable prices, well run, etc. Our experience was very positive with them last year, and that's compared to having chartered with well known firms such as Hinkley (ME), TMM (BVI), and others.
Wherever you end up--have a great time!
Best wishes,
Mark