Marine High Way: The Great Lakes St. Lawrence Seaway System

by OldSailor on September 1, 2008


highway_h2o GLSL_seaway_1

The Great Lakes St. Lawrence Seaway System is a deep draft inland waterway extending 3,700 km (2,340 miles) from the Atlantic Ocean to the the Great Lakes of North America up to the Port of Duluth. Annual cargo movement on this seaway system exceeds 200 million net tons (180 million metric tons). This Seaway is also called as Marine High Way H2O.

Some of the interesting features of the Great Lakes St. Lawrence Seaway System are:

  • The Great Lakes/St. Lawrence Seaway was built as a binational partnership between the U.S. and Canada.
  • Opened to navigation in 1959.
  • Administration of the system is shared by two entities
  • Ranked as one of the outstanding engineering feats of the twentieth century.
  • The Great Lakes that form the seaway system are:
    • Lake Ontario: Average depth-86 metres; Elevation-75 metres; St. Lawrence River connects it to Atlantic Ocean.
    • Lake Erie: Average depth-19 metres; Elevation-174 metres; Niagara River including Niagara falls connects it to Lake Ontario.
    • Lake St.Clair: Average depth-3.4 metres; Elevation-175 metres; Detroit River connects Lake St.Clair to Lake Erie.
    • Lake Huron: Average depth-59 metres; Elevation-176 metres; St.Clair River connects it to Lake St.Clair.
    • Lake Michigan: Lakes Michigan and Huron are hydrologically a single lake and is also called as Lake Michigan-Huron; they have the same surface elevation of 176 metres and are connected by 90 metres deep Straits of Mackinac. St. Marys River connects Lake Michigan-Huron to Lake Superior.
    • Lake Superior: Average depth-147 metres; Elevation-186 metres.
  • Except Lake Michigan all other lakes form part of the Canada-United States border.
  • The St. Lawrence Seaway includes 13 Canadian and 2 U.S. locks.

Here is the location map of the Great Lakes.


Here is the St. Lawrence Seaway profile view.


Here is a sketch showing the method of Locking a ship in the St. Lawrence Seaway.


Here is a photograph of the the Great Lakes St. Lawrence Seaway System.


Here are the Facts and Figures about the Great Lakes/St. Lawrence Seaway.

More information is available here at the Great Lakes St. Lawrence Seaway System and High Way H2O.

Here is an interesting video clip on St.Lawrence Seaway Management.

Except the Great Lakes location map, all other images are from the Great Lakes St. Lawrence Seaway System.

Update: September 02

Read more about St.Lawrence seaway from NYK Line.

Update: October 11

Unionized staff with the St. Lawrence Seaway could be in a legal strike position as of midnight on October 13, closing down the Welland Canal and the entire seaway to shipping traffic. Read more from Niagara This Week.

Update: October 15

The strike was averted after an agreement was reached between the St. Lawrence Seaway Management Corp., which runs the vital waterway and the CAW, which represents its 445 unionized employees. Read more from Financial Post.

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