Acoustic phase and amplitude fluctuations are compared to vertical and horizontal temperature fluctuations in very shallow water. Two examples are presented, one during a weaker internal wave event and one during a stronger internal wave event. The data were collected in 12 m of water depth off the beach of Panama City, FL, during April 1995. Each example is 5 min of acoustic data at 110 kHz, for a single source/receiver distance of 87 m and a repetition rate of 1 ping per second. Two 6-channel thermistor arrays, with a 1.2-m aperture, recorded temperature changes in the vertical and horizontal to within (plus or minus)0.01(degrees)C. The thermistor array is used to compute temperature spatial correlation lengths and times as well as for statistical comparison with acoustic phase and amplitude. Statistical differences in the acoustic phase and amplitude characteristics are presented as well as horizontal and vertical temperature distributions. Both phase and amplitude distributions are more similar to temperature distributions for the stronger internal wave event. Acoustic phase distribution most closely matches vertical temperature distributions.