Abstract

In this work, the estimation of design sea states is performed for an offshore area in the Evoikos Gulf, Greece. This area was selected for the development of an offshore aquaculture farm in the framework of the MATISSE project, whose aim is to design offshore fish cage nets, made of innovated materials that operate safely under extreme sea conditions. In this context, the wind and wave climate analysis and the estimation of extreme wave heights is of utmost importance for the rational design of the fish cages. Since the dynamic behaviour of any marine structure, and especially of the non-symmetric ones, strongly depends on the directional characteristics of sea states, directionality is taken into account as a covariate in the estimation of the n – year (n = 10,20, … ,100) design value of significant wave height, HS. The wind and wave climate analysis is based on long-term time series of wind speed and direction at 10 m above sea level and high spatial and temporal resolution wave spectral parameters data. A comparison between the extreme values obtained from the directional and the non-directional extreme value analysis of HS revealed important differences, rendering the offshore fish cage design a very delicate procedure, especially in non-unidirectional sea states.