In December 1918, Sinclair sallied into Estonian and Latvian ports, sending in troops and supplies, and promising to attack the Bolsheviks "as far as my guns can reach".

On the night of 4 December, the cruiser HMS Cassandra struck a German-laid mine while on patrol duties north of Liepāja, and sank with the loss of 11 of her crew.

The Estonian Prime Minister asked Britain to send military forces to defend his capital, and even requested that his state be declared a British protectorate.

[10] British cruisers and destroyers soon sailed up the coast close to the Estonian-Russian border and laid down a devastating barrage on the advancing Bolsheviks' supply lines.

In April 1919, Latvian Prime Minister Kārlis Ulmanis was forced to seek refuge on board the Saratov under the protection of British ships.

Walker, which acted as a lure, suffered some damage and two of her crew were wounded, while the other British destroyers eventually disengaged when they came too close to Bolshevik coastal artillery and minefields.

[16] Cowan also requested that Finland allocate a squadron of ships to provide additional protection for the anchorage as well as to take part in the security and patrol duties in the area.

[18] A flotilla of British Coastal Motor Boats under the command of Lieutenant Augustus Agar raided Kronstadt Harbour twice, sinking the cruiser Oleg and the depot ship Pamiat Azova on 17 June as well as damaging the battleships Petropavlovsk and Andrei Pervozvanny in August, at the cost of three CMBs in the last attack.

[24] The first raid was intended to support a significant mutiny at the Krasnaya Gorka fort which was eventually suppressed by the 12 in (300 mm) guns of the Bolshevik battleships.

[16] In the autumn of 1919, British forces—including the monitor HMS Erebus—provided gunfire support to General Nikolai Yudenich's White Russian Northwestern army in its offensive against Petrograd.

The British monitor Erebus attempted to assist in the siege of Krasnaya Gorka from 27 October, dislodging the defenders of the local fortress with its 15-inch guns, but by this time the White and Estonian forces were in retreat.

[25] The White army's offensive ultimately failed to capture Petrograd and on 2 February 1920, the Republic of Estonia and Bolshevist Russia signed the Peace Treaty of Tartu which recognised Estonian independence.