Polska Żegluga Morska known as Polsteam or PŻM, is a cargo ship operator based in Szczecin, Poland. Polsteam is a state-owned enterprise with around 3,000 employees.

The St. Lawrence Seaway is a system of locks, canals, and channels in Canada and the United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North America, as far inland as Duluth, Minnesota, at the western end of Lake Superior. The seaway is named for the St. Lawrence River, which flows from Lake Ontario to the Atlantic Ocean. Legally, the seaway extends from Montreal, Quebec, to Lake Erie, and includes the Welland Canal. Ships from the Atlantic Ocean are able to reach ports in all five of the Great Lakes, via the Great Lakes Waterway.