Beginning in 1981 expendable bathythermography (XBT) temperature sections, down to 60 meters, have been made two or three times per month between 20¿N and 20¿S along the ship of opportunity line from Europe to Brazil. Three thermal zones are described: the Guinea dome at 10¿N-15¿N, the equatorial region, and the Brazilian warm waters between 2¿S and 18¿S. The Guinea dome is characterized by a shallow thermocline with litte seasonal cycle and a doming or surfacing of the isotherms. In the equatorial region the thermocline is almost flat but moves up and down with the season and the changes in the trade winds. In the Brazilian warm waters the mixed layer is always thick with some seasonal cycle and the thermcline spreads from 100 meters down to the maximum depth of the measurements. The presence of absence of the major currents is infered from the slopes of the thermocline. The most striking event of the period is the development of a warm anomaly, in conjunction with light trade winds, during the southern hemisphere warm seasons of 1982, 1983 and 1984, reaching +1.5¿C over a large area in April 1984.