The 18 August 1919 raid on Kronstadt (also known as Operation RK or the Scooter Raid) was an attack by Royal Navy coastal motor boats (CMBs) and Royal Air Force aircraft on the Bolshevik Baltic Fleet at its home base, during the Allied intervention in the Russian Civil War. The Allies were operating in the Baltic Sea to support the independence of Estonia and Latvia, which were threatened by Bolshevik movements. The raid followed a similar one carried out by a single motor torpedo boat outside the harbour on 17 June 1919, in which Lieutenant Augustus Agar's CMB-4 sank the Bolshevik cruiser Oleg.