The flotilla was established as part of the
Pacific Fleet in August 1939 to guard coastal and maritime communications in the
Strait of Tartary and the
Sea of Okhotsk, with its main base at
Sovetskaya Gavan, under the command of
Counter Admiral Mikhail Arapov. The flotilla laid minefields off Sovetskaya Gavan during
World War II. In February 1943 Arapov was replaced by Counter Admiral
Vladimir Andreyev, who was promoted to
vice admiral on 5 November 1944. By the beginning of the
Soviet–Japanese War in August 1945, the flotilla included two patrol ships, eighteen trawlers, fifteen
Shchuka-class and
M-class submarines, 43 motor torpedo boats, seven large guard and patrol ships, as well as fifty patrol boats, two monitors, four minesweepers, two minelayers, the 365th Separate
Naval Infantry Battalion, and 280 aircraft of
Soviet Naval Aviation. Submarines and motor torpedo boats were organized into the 3rd Submarine Brigade and the 5th, 8th, and 9th Motor Torpedo Divisions. Two additional naval bases at
De-Kastri and
Nikolayevsk-on-Amur were part of the fleet, along with the Sovetskaya Gavan and
Kamchatka Fortified (Defensive) Districts and the
Nagaev Fortified Sector. Subordinated to the
2nd Far Eastern Front for the war, the flotilla laid minefields in the Strait of Tartary and the
Sakhalin Gulf beginning on the evening of 8 August in order to prevent Japanese retaliation. It was to capture
South Sakhalin in cooperation with the
56th Rifle Corps of the
16th Army. It was tasked with supporting an amphibious landing by the 365th Battalion and the
113th Rifle Brigade at the ports of
Toro and
Maoka, departing from Sovetskaya Gavan. Andreyev began the attack on the morning of 16 August by landing a 1,500-strong force of the 365th Battalion and the 2nd Battalion of the 113th Brigade at Toro, supported by seventeen warships and five transports. The attack captured the port and forced the retreat of three Japanese companies from it and nearby
Esutoru. This was followed by the 20 August landing of 3,400 men from the remainder of the 113th Brigade and a battalion of sailors at Maoka, which speedily defeated the Japanese defenders. The flotilla subsequently participated in the
Invasion of the Kuril Islands and the
Sungari Offensive during the Soviet–Japanese War, providing transport and launching air strikes on Japanese bases and ports. After the end of the war, it was disbanded in September. == References ==