The generation of ship bow waves is studied within the framework of potential
flow theory. Assuming the ship bow to be slender, or thin, a pattern of the flow is
derived using the method of matched asymptotic expansions. This method leads to
the determination of three different zones in which three asymptotic expansions are
performed and matched. To first order with respect to the slenderness parameter, the
near-field flow appears to be two-dimensional in each transverse plane along the bow.
However, it is demonstrated that three-dimensional effects are important in front of
the ship and must be taken into account in the composite solution. This leads to a
three-dimensional correction to be added to the two-dimensional solution along the
ship. The asymptotic approach is then applied to explain the structure of the bow
flow in connection with experimental observations and numerical simulations.