Formerly the yacht Winchester, she was purchased in the U.S. in June, 1915, fitted with a torpedo tube, and commissioned July 15 as a torpedo boat. Since she was unsuited for winter service n Canadian waters, Grilse left Halifax on December 11, 1916, for the Caribbean and was reported lost in a storm. She turned up at Shelburne, N.S. three days later, however. After several months' refit Grilse resumed her patrol duties until she was paid off on December 10, 1918. An effort was made to sell her in 1920, but no adequate bid was received, and during 1921-22 she was attached to a youth training establishment in Halifax dockyard. In 1922 she was sold to Solomon Guggenheim, who renamed her Trillora, and was still in his possession when, on September 21, 1938, she foundered in a hurricane on Long Island Sound.