As the global ocean observing has evolved over the past few decades a wide range of different types of measurement systems have been used and the data from these systems have been integrated to describe the varying structure of the ocean. Repeat hydrographic observations from MBT, XBT, CTD, and now ARGO have been used to document changes in the temperature and salinity of the ocean over the past 40-50 years. Meanwhile a host of different moored instrumentation has quantified the characteristic time-variability of oceanic flows such as the Gulf Stream, Kuroshio, and Malvinas Current and these systems are beginning to elucidate the time variability of more complex circulation systems such as the Meridional Overturning Circulation. Specific examples of how various components of the Global Ocean Observing System is unlocking the secrets of the oceans will be presented along with several examples of how assimilating models are beginning to improve their fidelity with the inclusion of data from satellites, the XBT and ARGO programs.