The present paper treats the hydrodynamic diffraction problem between multiple bottom seated elliptical
cylinders and regular surface wave trains. Linear potential theory is employed and the solution method is based
on the semi-analytical formulation of the incident and the diffracted surface waves’ potentials around the
elliptical bodies. Virtually, the mathematical process has many similarities with the well known analytical
technique which is implemented for the hydrodynamic interaction between arrays of circular cylinders and
regular wave train. Nevertheless, the problem associated with arrays of elliptical cylinders is admittedly more
complicated as it involves the ill-familiar periodic and radial Mathieu functions and requires the implementation
of an addition theorem, similar in concept with the Graf’s addition theorem for Bessel functions, but relevant to
the periodic and radial Mathieu functions