"st. sebastian" was built as a private motorboat of the same name by captain r. d. hardee at st. sebastian, florida. on 25 june 1917, the u.s. navy acquired her from her owner, j. w. taylor of marathon, florida, for use as a section patrol vessel during world war i. she was commissioned as uss "st. sebastian" (sp-470) on 9 august 1917.