Prediction of acoustic connectivity is the key to successful deployment of underwater acoustic communication systems, and in particular to deployment of multi-node networks. The connectivity is given mainly by the local sound propagation characteristics, which in turn are given by the spatial and temporal variation in the speed of sound. Such data are easily available as a by-product of hydrodynamic modeling. We demonstrate a network deployment analysis based on such data by a simple ray tracing approach. In a region of significant variability in bathymetry and hydrodynamics quite detailed sound speed data are found to be necessary, in order to avoid unnecessary conservatism in inter node hop-lengths. Such detail in time and space is very difficult and expensive to obtain by measurement, and the use of hydrodynamic modeling is a virtually the only alternative.