East from Whitestone by Way of Middle Ground to Falkner Island

The Sound begins in the narrow, steep-walled neck at Whitestone.
To the east, Execution Rocks are a hazard to navigation.

A dozen or so miles farther east, the Sound cuts deep harbors,
like Stamford and Huntington, into both shores.

The Sound gradually funnels wider and shoals.  By Smithtown Bay the waters have spread nearly 15 miles wide between Stony Brook and Westport.  Then the bottom rises to a 12-foot depth at Middle Ground which supports the Stratford Shoal light.