Russian Baltic naval organisation changed according to the Weekly Intelligence Summary No. 19 for the week ending 27 August 1921

An item reported that the post of the Chief of the Base was abolished and replaced by Commander of the Chief Port of the Baltic Sea. Petrograd [St. Petersburg] was now the chief military port of the Baltic Sea with Kronstadt and Schusselburg now ports of the 1st respectively 2nd category. Rumours were spread that discontent in the fleet could cause a new rising at Kronstadt.

Source

The National Archives, Kew Gardens, England CAB-24-127-74