Finland is one of the coldest, most northerly countries in the world. By some measures it may be the coldest country of all. Every winter the Baltic Sea freezes over!
Katajanokka, Helsinki
Ordinary ships cannot plow through sea ice without help. An icebreaker is a ship specially designed to operate in ice. It is built with a extra-strong bow (front of the ship) and is shaped so that the bow will ride up over the sea ice and then crush it. It leaves a lane of open water behind it.
You can see how the bow will ride up over the ice, crushing it
Every winter these icebreakers go to work, making sure that the ferries and cargo ships can get through from Europe to Finland. If they didn't keep the shipping lanes open, Helsinki and other ports would be closed.
Katajanokka, Helsinki
It's May now, so these ships have no work to do.
Sister ships
I am sure that on board these giant ships there are all the comforts of home - hot coffee, freshly baked pulla (cardamon rolls), warm beds, etc. Still, it makes me shiver to think of the work these crews do, breaking ice in the winter darkness of the Baltic Sea.
This one has a gun. It must be the Finnish Coast Guard
Finnish Icebreaker Fleet