WILLIAMSTOWN — The Williams-Mystic program has been selected to receive the National Maritime Historical Society's Walter Cronkite Award for Excellence in Education. The award, which will be presented May 2 at the National Maritime Awards Dinner at the National Press Club in Washington, D.C., recognizes individuals and organizations whose outstanding achievements in maritime education bring history alive for undergraduate students.Founded in 1977, the Williams-Mystic program offers students from Williams College and other colleges and universities the opportunity to take courses, pursue independent projects, and participate in three extended field seminars — all focused on the sea — for a semester at the Mystic Seaport in Mystic, Conn.