(MB: dp. 19; l. 73'3"; b. 11'8½ "; dr. 3' 10" (aft); s. 27 k.; cpl. 12; a. 1 3-pdr., 2 mg.)
Zenith (SP-61)—a motorboat constructed in 1917 at Camden, N.J., by the Mathis Yacht Building Co.—was acquired by the Navy on 21 April 1917 at Philadelphia from Charles Longstreet of that city and commissioned there on 23 April 1917. Assigned to section-patrol duty, Zenith conducted surveillance patrols to protect the harbors and estuaries of the 4th Naval District coastline from enemy incursion—primarily against submarine and mining operations. She served until hostilities had ended. She was decommissioned on 21 November 1918 just 10 days after the armistice. That same day, her name was struck from the Navy list; and Zenith was returned to her owner.
Zenith (SP-61) in a light gray finish, her hull number in small white characters at her bow, and a rapid-firing 3-pounder gun on her forecastle. This yacht was designed with the possibility of naval service in mind.