LAUSR

A one‐dimensional shallow water model is coupled with a floating boat which is assumed to be in hydrostatic equilibrium with the underlying water. Numerically, a semi‐implicit discretization of the shallow water equations also includes the Archimedes' floating conditions in such a fashion that the boat's vertical position and pitch slope are simultaneously adjusted to the computed flow field. The resulting algorithm is well‐posed, physically consistent, numerically stable, extremely efficient, and fully conservative. A few numerical tests are included to confirm the model's accuracy and performance.