"Rogue waves" are believed to be the cause of many accidents at sea. They are mostly individual waves of exceptional height and/or abnormal shape which cannot be detected with altimetry, as it averages measurements over several square kilometers.
Studies were conducted [Toffoli et al., 2003] for the European project MaxWave, to try and link the occurrence of such waves to some sea state properties simulated by a wave model. Altimetry data from Topex/Poseidon, Envisat and Jason-1 were then used to validate the results of wave model simulation . These proved that for two-third of the shipwrecks studied, the significant wave height was below 4 m. This means that if a ship had an accident under those conditions, it is likely that rogue waves were involved.