Great Lakes / St.Lawrence Seaway (Highway H2O) Facts
Opened to deep draft navigation in 1959.
Lock systems: ...
Vessel maximum: 225.5 m (740 ft.) ...
Channels maintained at 8.2 m (27 ft.)
People Also Ask
For your own safety, recreational activities such as swimming, water skiing, fishing, and diving are strictly prohibited in all Seaway canals, channels, pleasure craft docks, locks, weirs, and their approaches.
Since the St. Lawrence River is freshwater for much of its length, it freezes every winter, at which time specialized equipment is required and specific safety regulations come into effect.