The Spectral Ocean Wave Model (SOWM) has been an operational product at Fleet Numerical Oceanography Center since the mid 1970s; the Global Spectral Ocean Wave Model (GSOWM) was developed to replace it. An operational test of GSOWM, using buoy, ocean-weather-station, and ship-reported wave-height data for verification, was conducted during the winter of 1984/85 by several components of the Naval Oceanography Command. This test indicated that GSOWM was superior to SOWM and that both models exhibited root-mean-square significant-wave-height errors on the order of 1 m. Wave-height errors deduced from the ship observations were comparable to those calculated from the buoy data. The GSOWM scatter index, determined from the buoy and ocean-weather-station data and defined as the standard deviation of the model-predicted wave-height error divided by the mean observed wave height, averaged 0.34.
As a result of the study reported here, GSOWM replaced SOWM as the U.S. Navy's operational wave model in June of 1985. Examples of GSOWM output, illustrating both the capabilities and shortcomings of the model, are presented.