The design of the global Argo Array requires a 3 x 3 degree spacing of instruments between 60 ˚°S and 60 ˚°N, equivalent to 3300 floats. As of 31 Dec 2009, there were 3198 active floats, however only 2990 were reporting good quality data and many of these were deployed in marginal seas or in the high latitudes. Thus there are 2750 floats in the core Argo array, meaning that Argo has met or exceeded its design density only at mid-latitudes in the northern hemisphere. There is a shortfall of more than 500 floats in the Southern hemisphere. Therefore this region is a priority area for new float deployments.