Abstract
An anticyclonic mesoscale eddy, encountered during a hydrographic survey in the Sargasso Sea in September 1979, is described. Embedded in the eddy at a depth of 800 m was an isopycnal lens of anomalous water which extended 150 m vertically and ∼40 km horizontally. The source of the lens is not known but may be related to frontal processes in the area.