Meddy Bobby was found near 34.75°N, 23.5°W in March 1992, some 1500 km from the Strait of Gibraltar. The meddy core had a maximum salinity of 36.531 psu at a depth of 1320 m. A detailed hydrographic survey defined the temperature, salinity, oxygen, nitrate and silicate structure of the meddy. The velocity field was derived from the gradient equation, drogued Argos buoys and ADCP measurements. The property distributions suggest that about 1 km of the central water column (∼650–1600 m) was travelling with the meddy, though the vertical influence of the meddy extended over a much greater interval, >3km. Current structure reached the sea surface and isopycnals were depressed (by∼100 m) with respect to far field values even at a depth of 3 km. There was little evidence to suggest that significant mixing of the central core had yet taken place. Profiles in the meddy core showed the characteristic temperature maximum (at ∼ 775 m), the stability minimum (at ∼ 1250 m) and the stability maximum (at ∼ 1500 m) associated with Mediterranean Water outflow near the southwest corner of the Iberian Peninsula. Dynamic structures gave a core depth of ∼1100–1200 m, and at this level a number of well-defined structures were found that characterized the horizontal influence of the meddy. Surrounding an inner one (temperature >12.2°C, salinity >36.4 psu) of diameter about 25 km, in near solid body rotation (with centre period ∼3.7 days and relative normalized vorticity −0.5) there was a dynamically compatible broad potential vorticity front at a radius of ∼10–20 km. Maximum azimuthal currents (of ∼30 cm s −1) occurred at a radius of ∼22 km and at a radius of ∼27 km there was a water mass front where horizontal gradients of properties reached maximum values. This water mass boundary was thought to define the horizontal extent of the water actually travelling with the meddy, giving it an oblate discuss shape with aspect ration of 1.8%. Finally, at a radius of ∼40 km, where the potential vorticity gradient was no longer apparent, there was a perturbation front, indicative of mixing and exchange of water where the meddy penetrates the surrounding field.