The possible existence of freak waves is discussed. Our aim is not to present a final answer to the question raised in the paper rifle, but rather present some few evidences which, although not scientifically documented, seem to support the idea of a separate freak wave population. Extremes to be expected within a second order model for the surface elevation will be presented. Based on this, a possible definition of freak waves is suggested. A number of references discussing observations of giant waves are briefly reviewed and commented upon in view of the selected freak wave criterion. As a follow up to the observations of giant waves, the paper is briefly discussing some ongoing research on the possible modeling of such events.
A number of incidents of reported damages to ships and offshore platforms suggest the existence of unexpectedly large waves. Such waves are often referred to as freak waves, abnormal waves, or the "one from nowhere", indicating that observers over the years have considered these events as something beyond the extreme waves typically experienced by marine structures. Are such waves extremely rare realizations of a typical, slightly non-Gaussian population? - or - Are they typical realizations from a rare strongly non-Gaussian population? If the first question can be answered by "yes", then these waves are in principle accounted for by the present design practice, providing that this practice properly accounts for the typical but slight deviation from the Gaussian assumption regarding the surface process. If, on the other hand, a thorough assessment concludes that the observed giant waves most likely are realizations from a very non-Gaussian surface process, emphasis has to be given to the physical mechanisms that are governing these events.
