Bras d'Or Lake occupies the interior of Cape Breton Island in Nova Scotia, covering approximately 3,500 square kilometres. It is a tidal estuary with connections to the North Atlantic Ocean, giving it a roughly 50/50 mix of salt and fresh water. This unique character earned it designation as a UNESCO Biosphere Reserve. The lake is sometimes described as the world's largest inland sea, with a central basin extending 20 to 40 miles in places and numerous arms, basins, and channels radiating outward. The surrounding landscape consists of high rolling headlands in most areas, transitioning to lower terrain with islands and deep channels in places like the Malagawatch and Basins area to the northwest.

The scale of the lake is a primary consideration for paddlers in small human-powered craft. The central basin is large enough that wind can generate significant wave action, making conditions comparable to open coastal paddling. Fog is also a documented hazard, capable of reducing visibility to the point where shore disappears entirely. Paddlers should plan routes that allow for sheltered travel along arms and bays rather than crossing the open central basin.

Access to the lake is available at several points. Ross Ferry is a community-managed day-use area with a boat launch on the Bras d'Or. The Baddeck Yacht Club also has a launch, and the village of Baddeck on the lake's northern shore serves as a central hub with a public wharf, restaurants, shops, and the Alexander Graham Bell National Historic Site nearby. The lake is also accessible via the St. Peter's Canal, which connects it to the Atlantic through a lock and swing bridge at the southern end.

A mapped water route of approximately 86 miles runs point-to-point near Orangedale, and a longer circumnavigation of roughly 350 kilometres has been completed by paddlers. The lake supports kayaking, canoeing, and stand-up paddleboarding. Notable landmarks along the shores include Beinn Bhreagh, the former estate and burial site of Alexander Graham Bell, visible from the water near Baddeck. The lake's arms and bays offer numerous sheltered anchorages and camping opportunities, with wooded rolling hills and scattered small communities characterizing much of the shoreline.