HM Submarine Ocelot Built for Cold War service, so an air of secrecy still hangs over Ocelot's activities - although we know she travelled over 90,000 miles. Explore her at Chatham, along with the 19th-century navy vessel HMS Gannet( still being restored) and Second World War destroyer HMS Cavalier. The Historic Dockyard, Chatham, Kent (01634 823 807). Mon-Sun 10am-6pm (last admission 4pm), £9.50, concs £7, under-16s £6. www.chdt.org.uk.