Helsinki, Finland: Polaris, the Icebreaker

Finland has a huge interest in keeping the shipping lanes open during the winter. Many of the supplies that the country needs to exist enter the country that way, and a little ice can't get in the way of that.

Therefore, it's not surprising that the country relies on huge icebreakers to keep the water flowing. The first one arrived in 1890, and proved that the water could be kept relatively clear year-round. Sadly, Finland had to hand over its icebreakers to the Soviet Union as part of reparations for World War II, and it took until the 1950s for the nation to get back into the icebreaking business. 

A number of ships have filled that role over the years since then, but Polaris is the biggest. It's also environmentally friendly as these things go. As I recall, the boat essentially pushes on to the ice, and the weight of the vehicle crushes the ice to reveal the water below. 

A photo of it in June isn't too interesting. It's better to see it in action.