From June 28 to November 23, 1979, sea level fluctuations at three locations on the western side of the Gal¿pagos Islands were measured with shallow bottom-moored pressure and temperature gauges. Gauges were deployed at 1¿24'N,0¿, and 1¿S. The sea level variations were dominated by a highly coherent low frequency fluctuation with a period of the order of 100 days. In addition, high-frequency spectral peaks were observed with periods of 5.3 and 2.8 days. Temperature fluctuations also showed the dominant low-frequency change and the high-frequency spectral peaks; however, the temperature fluctuations were less coherent because of the thermal front in this region. Empirical orthogonal functions of the pressure gauge data showed that most (95%) of the low-pass filtered data could be explained by the first mode. This mode had a meridional shape consistent with a first baroclinic mode equatorial Kelvin wave. The second mode accounted for about 3.6% of the variance with periods from 15 to 5 days. Its shape was consistent with a first baroclinic mode mixed Rossby-gravity wave. The higher frequency peaks occur at frequencies where equatorial trapped inertial-gravity waves have zero zonal group velocity.