Guilford Harbor is located at the mouth of the East River, about one mile southwest from the center of Guilford. It is used principally by fishing and recreational craft.  

The project, completed in 1957, provides for:  

• A 0.8-mile-long channel, six feet deep and 100 feet wide, extending from Long Island Sound, through the harbor, to the anchorage area on the East River;
• A 1,500-foot-long anchorage area on the East River, six feet deep and 200 feet wide, ending at the mouth of the Neck River; and
• An 880-foot-long branch channel, six feet deep and 60 feet wide, up Sluice Creek and ending at Whitfield Street, just beyond the state wharf.