Recent uses to which tide records have been put have exposed limitations of the nonlinear tide well with an orifice. By replacing the orifice with a long horizontal pipe connection, the system becomes essentially linear and the limitations of the conventional system no longer apply. The analysis in this paper shows that unsteady effects in the pipe flow produce the main features of the frequency response of the system; the hydrodynamic filtering of waves due to the depth of the pipe connection and the effect of the inertia of the water in the well are relatively unimportant....