White earthenware plate, inscribed on the back: 'To commemorate the opening of the ST LAWRENCE SEAWAY by HM Queen Elizabeth II Canada 1959'. The front of the plate is printed in colour with a map of the Great Lakes. Above, portraits of Queen Elizabeth II and the Duke of Edinburgh, 'CANADA' on a ribbon above, the royal yacht 'Britannia' below. Beneath the map another portrait of President Dwight David Eisenhower (1890-1961) 'THE UNITED STATES OF AMERICA' on a ribbon below. The edge of the plate is decorated with four pairs of crossed Red Ensigns and US flags in colour, and it has a moulded and gilt rim. The maker's mark is printed on the base.