In this spectacular feature-length documentary, oceanographer Jacques Cousteau and an NFB crew sail up the St. Lawrence River to the Great Lakes on board the specially equipped vessel, the Calypso. They explore the countryside from their helicopter and plumb the depths of the waters in their diving saucer. They encounter shipwrecks, the Manicouagan power dam, Niagara Falls, the locks of the St. Lawrence Seaway and an underwater chase with caribou.

• Documentary