Out of the military base 'Lombardsijde - Nieuwpoort' shooting exercises are organized on a regular basis. For safety reasons, part of the sea is closed off for all shipping during the exercises. In the Notices to Mariners nr 1 you can see which sectors are reserved for the shooting exercises. You can also find them on the nautical charts.
Shooting exercises are normally never organized on Saturdays, Sundays, legal holidays or during school holidays.