This note is concerned with the problem of forced motion due to a vertical circular cylindrical wave-maker immersed in a liquid with an inertial surface composed of uniformly distributed floating particles. The techniques of Laplace transform in time and Weber transform in the radial co-ordinate are used to obtain the velocity potential and hence the inertial surface depression. For the special case of a time-harmonic wave-maker, the potential function is analysed for its steady-state development. It is shown that if the inertial surface is "too heavy", the disturbance due to the wave-maker remains confined within a short distance only. © 1989.