The Russian navy suddenly erupted and occupied the Baltiysk region, leaving the entire European world stunned; many believed that the Kingdom of Prussia was doomed.
Open the map and you'll see that the Prussian coastline is all in the Baltic Sea, which is the sphere of influence of the Russian navy.
Ever since the outbreak of the war, the Danish Navy has blocked the Prussians' maritime transport channels, and strategic materials supported by England and France could only be transported by land.
In the early stages of the war, the Tsarist Government ignored the role of the navy, not attacking the Prussian coastal areas and merely confronting them on land, which meant the Kingdom of Prussia was still able to fight.
Now it was different; unable to break through on land for a long time, the Russians turned their sights to the sea, using their naval advantage to strike the Kingdom of Prussia.