Canadian Bird-class patrol vessel

The Bird-class patrol vessels were a class of seaward patrol vessels operated by the Royal Canadian Navy (RCN) during the Cold War. The class derives its name from large birds found in Canada and was designed by the RCN as a replacement for the remaining Second World War-era Fairmile motor launches used for coastal patrol.
Design.
Bird-class patrol vessels were designed for harbour patrol, training and anti-submarine warfare. Constructed of wood and aluminum, the Bird class displaced . The vessels were long overall, with a beam of and a draught of . They had a complement of two officers and nineteen ratings.
The Bird class were powered by diesel engines creating connected to two shafts. This gave the ships a maximum speed of . The vessels were armed with one 20 mm gun and a Hedgehog anti-submarine mortar.
Service history.
"Loon" was the first to commission, on 30 November 1955 at Toronto, Ontario. The vessel sailed to Halifax, Nova Scotia in December through treacherous ice conditions. "Cormorant" and "Mallard" were commissioned on 16 July 1956 at Midland, Ontario and Penetang, Ontario respectively. "Blue Heron" commissioned on 30 July 1956 at Orillia, Ontario and was allocated to the Royal Canadian Mounted Police Marine Division based at Halifax.
In 1961, "Cormorant", "Mallard" and "Loon" were assigned to Atlantic Command as harbour patrol craft. In April 1961, "Mallard" was deployed to rescue the crew of the fishing vessel "Ocean Wave" which had run aground off Nova Scotia. The heavy seas prevented rescue by ship and the crew were taken off by helicopter.