Baie Tasiujaaluk, also known as Leaf Basin, is a vast coastal bay system in Nunavik, Quebec, characterized by its extreme tidal range. The tides in the basin regularly exceed 15 meters, which is the single most critical factor for paddlers to plan around. This immense tidal exchange governs all access, currents, and hazards. The northern village of Tasiujaq is situated on the shores of Leaf Lake at the head of Deep Harbour, providing a potential access point. The area lies just north of the tree line in a transition zone from shrub tundra to arctic tundra. A low tide harbour exists on Rowe Island, approximately five kilometres north of the village, which may serve as an alternative launch or take-out site, but its usability is entirely dictated by the tide stage.

The paddling environment is exposed and remote, with the basin consisting of interconnected areas: Leaf Lake, Leaf Passage, and Leaf Bay. The high, powerful tides will create strong currents, especially through the narrower passages, requiring careful timing to paddle with the tidal flow. Wind exposure across the open water can be significant, and the surrounding landscape of sedimentary and metamorphic bedrock creates cliffs and islands. The region is ecologically rich, with frequent sightings of marine mammals like seals and belugas, and many seabirds. Gyrfalcons and peregrine falcons nest on the islands and cliffs. The area is also known for Arctic char and Atlantic salmon. Paddlers should be fully self-sufficient, as there are no indicated facilities or amenities specifically for boaters beyond the community infrastructure of Tasiujaq. The area marks the final destination for canoeists descending the Leaf River.