into target tugs and saw use at units in Abbotsinch, Gosport, Crail, and Arbroath to help train pilots, starting in 1939. On 4 January 1939, two Sharks were taken up by No. 4 Anti-Aircraft Co-Operation Unit in Seletar, Singapore. During the Dunkirk evacuation conducted between 26 May and 4 June 1940, numerous Sharks flew across the English Channel to spot and illuminate Kriegsmarine E-boats using flares, they were otherwise unarmed; these operations were hindered and eventually stopped by poor weather conditions. Widespread use of the Shark III for the training of aerial observers and navigators proceeded as far afield as Trinidad; its use in this role continued to as late as 1942. Numerous Sharks would eventually be based at RAF Seletar as target tugs. During January 1942, the type was used to conduct patrol missions and even bombing raids against units of the Imperial Japanese Army as it advanced into Malaya. Overseas operators On 10 April 1935, Blackburn successfully secured a contract over rival firms from the United States, Germany, Czechoslovakia, and Italy valued at £50,000 from the Portuguese government for six seaplanes. Designated Shark IIA, these were largely identical to FAA aircraft, save for being equipped with different armament carriage arrangements - some could only be armed with torpedoes. The Portuguese Navy took delivery of the aircraft in mid-1936, stationing them at Bom Succeso on the River Tagus outside Lisbon for coastal defense duties. On 22 October 193, a long distance non-stop flight was conducted by a Portuguese Shark between Bom Succeso and RAF Calshot, carrying a diplomatic dispatch to London and returning six days later. During 1936, the Royal Canadian Air Force (RCAF) purchased seven Blackburn Shark II (760 hp/570 kW Tiger VI), the first four of which were shipped in September of that year. It was initially flown by No 6 (TB) Squadron, later operating as No 6 (BR) Sqn, to perform shipping patrols off the west coast of Canada. The type was reportedly appreciated for its rugged design and ease of maintenance, particular when operated from remote areas far from well-equipped workshops. The Shark became an element of a wider plan to bolster Canada's domestic production of aircraft; during early 1939, a pair of Shark IIIs (800 hp/600 kW Pegasus III) were supplied by Blackburn to serve as pattern aircraft for a further 17 aircraft that were locally produced by Boeing Aircraft of Canada at their