The collegiate coaching carousel has spun at a dizzying pace since racing wrapped in June. Among those making moves is Boston University, which tapped Ohio State University associate head coach Madeline Davis for its new director of women’s rowing. The former Princeton University lightweight and U.S. under-23 team member will have her hands full in Boston, guiding both the Terriers’ open and lightweight women’s squads. “This is an exciting time for Madeline, and even more exciting for BU,” said Ohio State women’s coach Andy Teitelbaum. “To have one of the most talented young coaches in America leading your program is a rare moment.”