The extreme wave height for design of an offshore wind turbine located in shallow water zone is
calculated based on Goda’s theoretical wave deformation model in accordance with requirement of
exceedance probability specified in IEC61400-3. Goda’s approximation formula for the maximum wave
height is adjusted for estimation of the extreme wave height with exceedance probability in IEC 61400-3.
Furthermore, incipient depth of wave breaking and its approximation formula are obtained. Comparisons
are conducted between the extreme wave heights by the Battjes & Groenendijk’s wave model and the
Goda’s wave model.