Beaufort scale used in Taiwan and mainland China, which are often affected by typhoons. Internationally, WMO Manual on Marine Meteorological Services (2012 edition) defined the Beaufort Scale only up to force 12 and there was no recommendation on the use of the extended scale. Wind speed on the 1946 Beaufort scale is based on the empirical relationship: Where "v" is the equivalent wind speed at 10 metres above the sea surface and "B" is Beaufort scale number. For example, "B" = 9.5 is related to 24.5 m/s which is equal to the lower limit of "10 Beaufort". Using this formula the highest
MS Estonia starboard because of poor cargo distribution. According to the final disaster report, the weather was rough, with a wind of , force 7–8 on the Beaufort scale and a significant wave height of compared with the highest measured significant wave height in the Baltic Sea of . Esa Mäkelä, the captain of "Silja Europa" who was appointed on-scene commander for the subsequent rescue effort, described the weather as "normally bad", or like a typical autumn storm in the Baltic Sea. All scheduled passenger ferries were at sea. The official report says that while the exact speed at the time of