One of the major reasons for observing the global ocean is to infer the transport properties of quantities important to climate, including heat, freshwater, carbon, oxygen, etc. Given the disparate observational techniques which formed the World Ocean Circulation Experiment, the only feasible approach is to combine the data with general circulation models (GCMs) to produce the required estimates. We demonstrate here preliminary global ocean circulation estimates based on an OGCM constrained by a variety of global data sets. The resulting model state is employed in an offline mode to simulate the ventilation of chlorofluorocarbon 11 (CFC11) into the ocean. Through a series of experiments, we demonstrate that including the tracer data itself in the state estimation procedure can provide additional constraints.