Navigation in extreme cold conditions, means repeated ice breaking in navigation channels and harbour basins. The broken ice resulting from this repeating procedure, is called ‘’ Brash Ice’’, in opposite to ‘’sea ice’’ which is formed statically in calm water. Just after an ice breaking event, caused by a vessel transit, there is a lot of water near the surface, exposed to freezing without the insulation that the static ice has with either a snow or a thick ice cover on top. This means faster formation of ice, compared to the case of static or sea ice. The main objective of this graduation study is the development of Brash Ice Growth Models (BIGMs), with the use of both analytical and numerical thermodynamic methods that would be able to predict the thickness of the total ice or brash ice layer developing immediately below a ship track transited by vessels, with the basic assumption being that all the ice grown remains within the ship track.