A global picture of the water column inventories of bomb-produced tritium is constructed from the GEOSECS data set. this picture is compared with that obtained by combining the bomb tritium input function of Weiss and Roether  with the bomb radiocarbon calibrated lateral redistribution model of Broecker et al. . While differences between the calculated and observed distribution exist, they are surprisingly small. Tritium distributions calculated using the lateral redistribution model provide predictions of the changes to be expected in the next few decades. Such predictions are essential to the design of sound strategies for continued monitoring of the tritium transient.