Footnote
a Icebreakers vary in size and construction, depending on where they operate—in harbors, on the open sea, or in the polar regions. This article focuses mainly on the icebreakers used on the open sea.
a Icebreakers vary in size and construction, depending on where they operate—in harbors, on the open sea, or in the polar regions. This article focuses mainly on the icebreakers used on the open sea.