  The Van Hove self correlation function of water confined in a silica pore is
calculated from Molecular Dynamics trajectories upon supercooling. At long time
in the $\alpha$ relaxation region we found that the behaviour of the real space
time dependent correlators can be decomposed in a very slow, almost frozen,
dynamics due to the bound water close to the substrate and a faster dynamics of
the free water which resides far from the confining surface. For free water we
confirm the evidences of an approach to a crossover mode coupling transition,
previously found in Q space. In the short time region we found that the two
dynamical regimes are overimposed and cannot be distinguished. This shows that
the interplay between the slower and the faster dynamics emerges in going from
early times to the $\alpha$ relaxation region, where a layer analysis of the
dynamical properties can be performed.
