Over a 1-month period (October 5 to November 6,1982) during the initial stages of the 1982--1983 El Ni¿o, hydrographic and velocity profiling measurements were made in the eastern equatorial Pacific by two research vessels. Track lines approximated a square, centered near the Gal¿pagos Islands with approximately meridional sections at 95 ¿W and 85 ¿W and nearly zonal sections at about 5¿N and 5 ¿S. Water mass characteristics and estimated currents of these sections are discussed. Sea surface temperature nearly everywhere was warmer than 25 ¿C (an anomaly of 2 ¿C--3 ¿C). The equatorial thermocline, represented by the 20 ¿C isotherm, was depressed by nearly 50 m at 85 ¿W and more than 100 m at 95¿W relative to a historical mean profile. Across 95 ¿W, estimated geostrophic (relative to 500 dbar) and directly measured near-equatorial velocity profiles indicated significant eastward surface flow. The South Equatorial Current south of the equator had disappeared. Estimated warm water transport (&sgr;t<24.5 kg m -3) indicated an influx into the region which was approximately that required to balance the observed low-frequency sea level change at the Gal¿pagos Islands. Temperature and salinity properties as well as the transport estimates indicated that this warm water came predominantly from the west.