'BS' (iv) was a British series of naval undertakings to lay the minefields of the East Coast Barrier off the coast of East Anglia (June/July 1940).

The ships involved included the coastal minelayer Plover and auxiliary minelayer Teviot Bank. However, 'BS19' on 26 June used Teviot Bank, destroyer minelayers Express, Icarus and Intrepid, and as escorts the destroyers Javelin and Jupiter.