The initial value problem for a completely
integrable shallow water wave equation is
analyzed through its formulation in
terms of characteristics. The resulting
integro-differential equations give rise to finite dimensional
projections onto a class of distributional solutions of the
equation, equivalent to taking the Riemann sum
approximation of the integrals. These finite dimensional
projections are then explicitly solved via a Gram-Schmidt
orthogonalization procedure. A particle method
based on these reductions is implemented to solve the wave equation
numerically.