Groceries, Beer, Wine, & Spirits
If looking for alcohol, you have: Hatch's Package Store, Nantucket Wine and Spirits, Murray's Beverage Store, The Islander, and Old South. Epernay and BRIX also carry all three and will probably have your most diverse wine selections.
Water Sport Gear
Tech & ShippingComputer Solutions is good to get your iPhone or computer fixed, and they have various computer supplies available as well. For shipping needs, there is FedEx , UPS, and USPS.