This sandy, 37-acre barrier island (shown as “Dead Neck” on charts) off Osterville and Cotuit is a popular spot among boaters along the south side of Cape Cod.
The island is managed by Massachusetts Audubon, whose staff may ask for a donation while you use the beach. Note that much of the island’s interior is off-limits to protect nesting shorebirds. From May through September, the island is patrolled by Mass Audubon’s Coastal Waterbird Program staff, who protect nesting areas, lead nature walks, and ensure compliance with sanctuary regulations.
You can access the protected backside of the island via the narrow channel that connects Cotuit and West Bays then gently nose your bow onto the sand to offload passengers and gear. This is a wonderful place for small children to splash around, and there’s a nifty tidal pool on the western end of the island to explore.