Gilbert, Robert P.Ou, Miao-jung2007-08-162007-08-162001-07https://hdl.handle.net/11299/3693This paper shows that under the assumption of the out-going radiation conditions at infinity, the time-harmonic acoustic scattered field off a sound-soft solid in a shallow ocean with a fluid-like seabed is unique in C2 (M1) C2 < (M2) C(Rh3 \ ). Here M1 is the water part, M2 the seabed, Rh3 the waveguide and the solid object. The associated modal problem is studied and a representation formula for the solution in terms of the Green's function is derived.