The Chesapeake Bay Retriever is a large-sized breed of dog belonging to the Retriever, Gundog, and Sporting breed groups. Members of the breed may also be referred to as a Chessie, CBR, or Chesapeake. Historically used by area market hunters to retrieve waterfowl, pull fishing nets, and rescue fishermen, it is primarily a family pet and hunting companion. They are often known for their love of water and their ability to hunt. Distinctive features include eyes that are very clear, of yellowish or amber hue, hindquarters as high or a trifle higher than the shoulders, and a double-coat that tends to wave on shoulders, neck, back, and loins. The waterproof coat feels slightly oily and is often associated with a slight musky odor. The hindquarters are especially strong and the toes webbed since excellent swimming ability is important for the Chesapeake. This breed is also known for its large and powerful chest, used to break apart ice when diving into cold water while duck hunting.