Map sheet number OL 3 in the detailed OS Explorer weatherproof Map series gives you the tools to discover the wealth of naval history that Portsmouth offers. The new replacement for the Explorer 119 map, the OL 3 covers the same area from Portsmouth stretching north through Fareham, Waterlooville, Droxford and Owslebury. The map also takes in a south westerly section of the South Downs National Park.