Geography. Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water. Australia. Channel Country, region of outback Australia in Queensland and partly in South Australia, Northern Territory and New South Wales.; Channel Highway, a regional highway in Tasmania, Australia.; Europe. Channel Islands, an …

Buttermilk Channel is a small tidal strait in Upper New York Bay in New York City, approximately 1 mile (1.6 km) long and 0.25 miles (0.40 km) wide, separating Governors Island from Brooklyn.The channel is marked by a number of navigation aids (green cans no. 5 and 7 at the northeast entrance, and green gong no. 1, marking low water off the tip of Governors Island).