This image shows the waterfront buildings and boats of Rockport Harbor, part of the town of Rockport, Massachusetts.
The description states:
MORNING AT EBB TIDE, ROCKPORT HARBOR, CAPE ANN, MASSACHUSETTS
–Cape Ann is the northernmost cape of Massachusetts, and Rockport sits at the extreme end of the Cape, surrounded on three sides by water.
This card was used and is dated 2 Jul 1964.