Grimsby is strongly linked with the sea fishing industry, which once generated wealth for the town. At its peak in the 1950s, it was the largest and busiest fishing port in the world. As a result of the Cod Wars with Iceland, this industry has been in decline for many years. In 1970 around 400 trawlers were based in the port, by 2013 only 5 trawlers remain based there. By comparison, 15 vessels are used to maintain offshore wind farms in the North Sea. The town still has the largest fish market in the UK, but most of what is sold
USS Cod use the same vertical ladders and hatches that were used by her crew. Cleveland can claim partial credit as "Cod"'s birthplace, since the submarine's five massive diesel engines were built at the General Motors Cleveland Diesel plant on Cleveland's west side. In addition, she also has unique attractions such as the 5 inch deck gun that still can be rotated by visitors and mock fired by "Cod"s volunteer crew. The "Cod" 's Mark IV Torpedo Data Computer is also fully restored, as well as other various parts on the submarine. The "Cod" memorial acquired two General Motors Model 248 engines