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 pass the locks on the Saint Lawrence Seaway because the ships are too wide. Only four bridges are on the Great Lakes other than Lake Ontario because of the cost of building structures high enough for ships to pass under. The Blue Water Bridge is, for example, more than 150 feet high and more than a mile long. The Great Lakes are used to supply drinking water to tens of millions of people in bordering areas. This valuable resource is collectively administered by the state and provincial governments adjacent to the lakes, who have agreed to the Great Lakes Compact