Times have changed though. There are published dates as to when the ranges will be open to the public (i.e no firing), but if the Army decides more practice is required then the ranges might be used. All MOD ranges are in use far more often these days- always check!
"Information about the range walks can be obtained from the Range Control Office (0900-1630 hrs Mon-Fri and during the weekends when the ranges walks are closed), Tel: 01929 462721 ext 4819/4859; or from the Guard room at any time, Tel: 01929 462721 ext 4824. "
"Offshore the sea danger area extends up to six nautical miles offshore between Lulworth Cove and St. Aldhelm's (St. Alban's) Head. Vessels are asked to keep out of the area at firing times. Full details can be found in the leaflet The Lulworth Ranges - Information for Mariners 2006"