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The large eddy that broke off from the Loop Current in July 1985 was the most extensively studied eddy ever to appear in the Gulf of Mexico. Other investigators have described its early evolution based on Lagrangian drifters and its later evolution using moored current meters in the western gulf. This paper provides additional insight on the early evolution of the eddy using results from air dropped expendable bathythermographs and air dropped expendable current profilers in early May, a hydrographic ship survey in mid July, and a detailed ship survey in August using expendable bathythermographs and a current profiler. The May survey established a center of circulation at about 26øN but showed that the eddy had not separated from the Loop Current. A maximum velocity of 171 cm/s was observed near the northern edge .of the feature. The evidence suggests that a large elongated eddy then separated from the Loop Current and later split into two smaller eddies. The July hydrographic cruise showed a clear separation of the large eddy from the Loop Current to the southeast. Two weeks later, the August survey showed an asymmetric eddy, with the maximum surface current 178 cm/s south of the center of circulation and 132 cm/s to the north. A wes. tern eddy named Ghost Eddy then separated from an eastern eddy named Fast Eddy. Using the c•.ent profiles and data from the ch-ifters, we constructed a simple kinematic feature model for eddies in the Gulf of Mexico.

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Oceanographic conditions in the Gulf of Mexico have been extensively studied from the summer of 1999 through the fall of 2000. These studies included cradle to grave surveys of Juggernaut Eddy; surveys in the Caribbean by several consortia; oceanographic surveys in support of hurricane research in the Gulf; measurements of inflow/outflow through the Yucatan Strait; and regional nowcasts and hindcasts of circulation. Several interesting phenomena have been observed during this period, including energetic bottom currents in excess of 2 knots and bottom furrows on the continental slope; the intrusion of one of the strongest eddies in a decade into the north-central Gulf leases; and strong midwater-column currents in SE Ewing Bank (~140 cm/s). This paper describes the observational data available and summarizes ongoing efforts to understand the oceanographic conditions during this period. Eventually, it is hoped that these efforts will lead to a better estimation of offshore structure design currents; an understanding of the dynamical causes of the strong mid-water-column currents; determining whether there is a link between the strong bottom currents at the base of the Sigsbee Escarpment and the Loop Current; and assessing the skill of the regional forecast/nowcast/hindcast oceanographic models.