St. Andrews Channel is a major, deep arm of Bras d'Or Lake, a large brackish inland sea on Cape Breton Island. It is one of two long channels formed by the Washabuck Peninsula, with a maximum recorded depth of 287 meters. The channel is part of the Bras d'Or Lake UNESCO Biosphere Reserve, characterized by largely undeveloped shorelines and significant bald eagle populations. The scenery along the channel is a key attraction, with quiet shoreline drives hugging its length, such as along Route 223 beginning near Iona. For paddlers, access may be restricted at the channel's entrance by a highway bridge with limited clearance, which restricts passage to small power craft, presenting a potential obstacle or navigational consideration for taller vessels. The tidal waters of Bras d'Or Lake, which include St. Andrews Channel, experience tidal exchange, though it is restricted at the lake's few connections to the Atlantic Ocean, resulting in brackish water with lower salinity than the open sea. The overall experience is peaceful and scenic. Big Harbour, located within the channel system, offers a good anchorage, while the Head of Baddeck Bay provides a protected and secluded area, suggesting potential launch points or sheltered paddling destinations. The lake's size is substantial, with the broader system spanning over 1,000 square kilometers, so paddlers should plan trips piecemeal and be prepared for potentially long distances and significant fetch that can generate waves in windy conditions.