She served in the Boston, Massachusetts, and Hampton Roads, Virginia, waterways until war's end when she was returned to her owner.

USS Inca, a 23-ton motor patrol boat, was one of a group of nine motor boats built by Herreshoff Manufacturing Company, Bristol, Rhode Island, in 1917 in the expectation that their private owners would make them available for First World War service.

A versatile craft, Inca was first assigned to the First Naval District and patrolled outer Boston Harbor.

Inca's job was to serve as rescue ship for aircraft from the Naval Air Station on flights over the Chesapeake Bay and Potomac River.

Inca was assigned 26 July 1918 to the Industrial Department, Hampton Roads, as a dispatch boat, and remained on this duty for the rest of her time in Navy service.