This is a picture of the bridge on Bridge Road, near the Orleans-Eastham line.  This is a place where Cape Cod Bay and Nantucket Sound are only about a 1/2 mile apart.  At times, due to record high tides, this half mile is breached by water. The little streams and rivers run
together, creating a passageway for a boat. 

This was the case when Cyprian Southack, a privateer for the King, was trying to get to the treasures of the pirate ship, Whydah. Southack was able to strategically run his boat across the Cape at this exact point, saving him the time of circling completely around Race Point in  Provincetown.