High Quality Content by WIKIPEDIA articles! Her Majesty`s Naval Base (HMNB) Devonport (HMS Drake), is one of three operating bases in the United Kingdom for the Royal Navy (the others being HMNB Clyde and HMNB Portsmouth). HMNB Devonport is located in Devonport, in the west of the city of Plymouth in Devon, England. It is the largest naval base in Western Europe and is the sole nuclear repair and refuelling facility for the Royal Navy. The collocated Royal Dockyard is owned and operated by the Marine division of Babcock International Group (BM), who took over the previous owner Devonport Management Limited (DML) in 2007. The BM operation is commonly called Devonport Royal Dockyard.