A brief general presentation of sea ice ridges is given on the basis of the literature published on the subject. The physical characteristics of a normal Baltic type ridge are researched in order to produce a basis of ridge data for calculations of the ice resistance encountering ships in sea ice ridges of the Baltic, first winter, type. To give the reader a wide view of the ridges, a general presentation about them is first given with a state of art review to Baltic ridge statistics. The main objective of this paper is, however, to introduce the physical characteristics of a Baltic ridge type, a first year ridge. The set of data should be as a representative and in convenient form to be used as input data for ship resistance calculations in Baltic type ridges. All ice-covered waters show a wide variety of ice formations. From the navigational point of view the most difficult obstacle is formed by ice ridges. The limits to the capability of a ship to navigate through ice-bound waters is generally determined by the ridges. In winter, the merchant ships in the Gulf of Bothnia are often stopped by these. In the Arctic heavy multi-year ridges form an obstacle still unpenetrable by any ship.