Great Lakes Waterway upbound direction is away from the St. Lawrence River (westerly or northerly except in Lake Michigan where upbound is southerly). Channels are marked with navigation buoys in constricted areas and pilots are required on foreign boats. Recreational boats can use or cross the ship channels, but the large boats, with limited maneuverability, have right of way. Map of the North American Great Lakes and the St. Lawrence Seaway from 1959, depicting the entire length beginning at the Gulf of Saint Lawrence in the east to the western-most terminus at Lake Superior. Great Lakes Waterway The Great Lakes Waterway is a
Great Lakes Waterway lake freighters to travel from the system's saltwater outlet to its far interior. The Waterway has larger locks and deeper drafts than the lower Seaway, limiting large freighters to the four lakes upstream of the Welland Canal and Lake Ontario and similarly restricting passage beyond the canal by larger ocean vessels. The two waterways are often jointly and simply referred to as the "St. Lawrence Seaway", since the Great Lakes, together with the St. Lawrence River, comprise a single navigable body of freshwater linking the Atlantic Ocean to the continental interior. Shipping channels separate upbound traffic from downbound traffic. The