  A study of the wave dynamics around a multiple fishing cage system is carried
out under the assumption of the linear water wave theory and small-amplitude
wave response. The Fourier--Bessel series expansion of the velocity potential
is derived for regions enclosed under the open-water and cage systems and in
the immediate vicinity. Further, the scattering between the cages is accounted
for by employing Graf's addition theorem. The porous flexible cage system is
modelled using Darcy's law and the three-dimensional membrane equation. The
edges of the cages are moored along its circumferences to balance its position
in the deep sea. The unknown coefficients in the potentials are obtained by
employing the matched eigenfunction method in conjunction with the
least-squares approximation method. In addition, the far-field scattering
coefficients for the entire system are obtained by expanding the Bessel and
Hankel functions in the plane wave representation form. Numerical results such
as the hydrodynamic forces, scattering coefficients, and power dissipation are
investigated for various cage and wave parameters. The wave loading on the cage
system can be significantly damped by the spatial arrangement, membrane
tension, and porous-effect parameter. Moreover, the far-field results suggest
that the cage system can also be used as a breakwater.
