Osterville Grand Island: Circumnavigation from Prince Cove Professional Review and Guide
"This circumnavigation is ideal for beginning kayakers: it’s a short but pleasant tour around Grand Island in protected waters, and you don’t need to double back on any sites. There’s a lunch spot on Oyster Harbors Beach, and you will pass the historic Crosby Yacht Yard, where a century ago the Crosbys built the famous Cat Boat with retractable centerboard for the Cape’s shallow waters.
Geographically, Osterville Grand Island is surrounded by three large, protected shallow bays—Cotuit to the west, North to the north, and West, oddly enough, to the east. They are connected by narrow channels and protected from the ocean by the barrier beach of Oyster Harbors and Sampsons Island, separated from the mainland by the Seapuit River. West Bay and Cotuit Bay both open to Nantucket Sound."