Throughout its history, the Royal Canadian Navy has deployed British-designed and built ships, from the HMCS Rainbow, which entered Canadian service in 1910 to HMCS Bonaventure and even today, with our less-than-stellar Victoria-class submarines. However, Canada really began to come into its own during the Cold War, relying less on the UK for military procurement. The first Canadian-designed warship was the St.Laurent-class destroyer escort. Seven were commissioned between 1955-57, HMCS St.Laurent, HMCS Skeena, HMCS Ottawa, HMCS Fraser, HMCS Assiniboine, HMCS Saguenay and HMCS Margaree. Though based on the British Whitby-class frigate, the St.Laurent-class incorporated some distinctly Canadian features, notably the rounded deck edge to prevent ice buildup on the foredeck. The St.Laurent-class ships also included several design features for dealing with nuclear, chemical and biological attack, including sealed crew quarters and a pre-wetting system to wash away contaminants. The later Restigouche-, Mackenzie- and Annapolis-class destroyer escorts were modified versions of the St.Laurent-class design. The seven St.Laurent-class ships underwent DDH conversion in 1963-66, allowing them to take advantage of the newly-developed 'beartrap' helicopter retrieval technology and all were equipped with a CHSS-2 Sea King helicopter. The last St.Laurent-class destroyer escort, HMCS Fraser, was decommissioned in 1994.