咸水
Saguenay Fjord, the park's namesake, has a length of and a width that varies between and . The fjord has an average depth of , with the deepest point being . The cliffs along the fjord have an average height of , reaching a maximum height of . Saguenay Fjord flows into the St. Lawrence River; salt water from the river flows under a layer of freshwater originating from Lac St. Jean. Salt water takes up 93% of the water volume inside the fjord.