What significant body of water did Jacques Cartier discover?

Jacques Cartier is credited with the discovery of the St. Lawrence River during his explorations in the 16th century. This river was significant as it served as the main waterway for the early exploration of Canada, providing a route for trade, settlement, and communication between the indigenous people and European settlers. Cartier's expeditions in 1534 and later years helped to lay the foundation for France's claims in North America, particularly in what is now Canada. The St. Lawrence River is not only crucial for its geographical importance but also for its role in the history of European colonization in the region. The other bodies of water mentioned are associated with different explorers and developments, making them less relevant to Cartier's discoveries.