After her boyfriend leaves her to go to college, Tammy Tyree (Sandra Dee) sets off on her houseboat and docks near Seminola College, where she enrolls as a student herself. Soon, she's working for Mrs. Call (Beulah Bondi) to pay her tuition, and falling for handsome professor Tom Freeman (John Gavin). Tammy and Mrs. Call also become close friends, with Mrs. Call moving onto Tammy's houseboat and giving her gifts -- much to the dismay of Mrs. Call's jealous niece, Suzanne (Julia Meade).