The dynamics which control the spread of tracers in the N.W. European Shelf Seas are reviewed. The perspective of this review is to allow a comparison with the vastly different regimes found in Australian waters. Whilst these N.W. European Shelf Seas are dominated by the influence of the M2 semi-diurnal tide, the Gulfs off South Australia have significant diurnal constitutents and a peculiar near equality of M2 and S2-producing 'dodge' tides. Nevertheless, generalised expressions for both the annual mean and the seasonal amplitude of sea surface temperature (derived from North Atlantic data) are generally applicable. The greater sensitivity of diurnal tidal constituents to bed friction coupled with the proximity to the related inertial latitude suggests that tidal propagation models may require more tuning of the bed stress coefficient. However the greatest contrast is for 'estuaries' where the excess of evaporation over precipitation and river flow produces 'inverse estuaries' unknown in Europe. Whilst flushing time concepts can be used in similar fashions, the extraction of tracers from such estuaries occurs close to the bed via 'inverse' salt wedges. This contrast with mean surface extraction in European estuaries will have significant influences on the related ecology. A 'Future Work' section describes recent developments and plans to extend marine forecasting via Operational Oceanography. Whilst Australian requirements will differ considerably, the need to maintain awareness and adopt common practices is important to fulfill the wider goals of GOOS-the Global Ocean Observing System.