Besides still water loads, the wave loads play a significant role in the ship’s survival. Using the detailed analysis of ships’ incidents of the Norwegian fleet for 1970-78 and of the Japanese fleet for 1965-74, Alexandrov (1983) noted that the greatest number of failures occurs in calm and moderate weather with weak wind and a condition of the sea from quiet to average. Yuniter (1973) also notes that failures usually occur at rather favorable condition of the sea (a wave and a wind less than 5 Beaufort scale), which usually allows to neglect the wave load during salvage operations.
However, such conclusions can be made only for cases that did not end with ship’s loss. If one considers only accidents of sea-going ships, the importance of weather conditions increases. So, according to Lloyd’s Register (1988), in 1987, of 43 ships lost due to groundings, 18 ships were lost during a storm.