Built for Derwent Trawlers Grimsby Ltd, the parent company of the Ross Group Ltd., [i]Ross Cougar[/i] GY 531 was one of an eventual fleet of twelve "Cat" class trawlers from the shipbuilding yard of Cochrane & Sons (Selby, Yorkshire - UK).

The naming of the "Cat" class trawlers is an interesting tale. A group of children from a Grimsby School were approached by the Ross Group and asked to suggest names in the "big cat" family, for the twelve new trawlers. The names were submitted after great thought and deliberation by the children. Tiger, Leopard, Jaguar, Panther, Cougar, Cheetah, Lynx, Jackal, Puma Genet, Civit and finally "Zebra".

With the formation of the British United Trawlers (BUT) group in 1969 the Ross Jaguar, along with all the other vessels in the group, adopted the distinctive funnel markings of a broad white band on black with the legend BUT in dark blue.

With the state of the fishing industry in 1982, the once great trawler fishing fleet had been drastically reduced in the wake of the third and ultimately most damaging "Cod War". B.U.T. were determined to continue for as long as possible and kept the fleet at sea. A little respite, but time was running out. All eleven of the remaining Cat Class trawlers, (the 12th trawler, Ross Puma met an early and untimely demise when on the 1st. April 1968 - she was wrecked off Hoy in the Pentland Firth), continued as trawlers and the Ross Cougar has the distinction of landing the last catch at Grimsby in July 1985.