How Ocean Ships Reach Toronto: The St. Lawrence Seaway Connection

Toronto sits on Lake Ontario, ~1,300 km (800 mi) from the Atlantic—yet oceangoing vessels reach its harbor regularly via the St. Lawrence Seaway.

The Route

1. Atlantic Ocean → Gulf of St. Lawrence.
2. St. Lawrence River — 1,197 km (744 mi) to Lake Ontario.
3. Seven locks (Montreal to Lake Ontario): St. Lambert, Côte Ste. Catherine, Beauharnois (2), Snell, Eisenhower, Iroquois. Total lift: 73 m (240 ft).
4. Lake Ontario → Toronto Harbour (Western Gap / Eastern Gap).

Seaway Specs

• Opened 1959 (Canada-US joint project).
• Max vessel: "Seawaymax" — 225.5 m (740 ft) length, 23.8 m (78 ft) beam, 8.08 m (26.5 ft) draft, 35.5 m (116 ft) air draft.
• Season: Late March – late December (ice closes winter).
• 4,000+ transits/year; 40M+ tonnes cargo (grain, iron ore, steel, cement, project cargo).

Toronto Port

• PortsToronto operates: Marine Terminal 52 (bulk), Cruise Ship Terminal (seasonal), Billy Bishop Airport (island).
• Turning basin, dry dock, rail/road connections.

Why It Matters

Great Lakes-St. Lawrence System = 3,700 km (2,300 mi) inland navigation. Toronto is a freshwater port with ocean access—unique economic advantage.

Ships don't sail "overland"—they climb a liquid staircase of locks from sea level to 75 m above.