Section patrol craft

A Section Patrol Craft was a civilian vessel registered by the United States Navy for potential wartime service before, during, and shortly after World War I.

In 1916, with World War I raging abroad, the U.S. Navy began a registry of privately owned pleasure craft and yachts that were available for patrol service in the event the United States was drawn into the conflict, which it eventually entered on 6 April 1917.

Naval Registry Identification Numbers were assigned in a "Section Patrol" series beginning with SP-1 and ultimately extending to well over 4000.

The latter category included some ships that served in the Navy without SP or ID numbers between 1917 and 1919.

They can therefore be considered precursors of the U.S. Navy hull number system instituted in July 1920 and still in use today.

USS Kanawha II , later renamed USS Piqua , was a private yacht prior to her World War I Navy service. She received the section patrol number SP-130.
The troopship America was the former German ocean liner Amerika . She was assigned the U.S. Navy ID number 3006.