A few experiments are reported in which thirty‐millisecond signals of 24‐kc sound were emitted in the ocean every second at depths of 150, 300, 500, and 1000 ft., by a relatively non‐directional projector, and were received by similar units at the same depths after having traveled 100 to 3000 yards. A recording technique was used which made it possible to resolve the direct and surface‐reflected components. Transmission conditions near the surface were poor during the experiments, and the transmission was found to improve as the projector and receiver depths increased. The average attenuation at the greatest depths was about 6 db/1000 yd. in addition to the loss caused by an assumed inverse‐square divergence of the sound energy. Although the emitted signals had rectangular envelopes and were all of the same amplitude, the amplitudes of the received signals fluctuated from signal to signal and within each signal. The fluctuation of the directly transmitted signals showed a general tendency to increase with range in proportion to the square root of the range. The magnitude of this fluctuation changed from about 10 percent of the average amplitude at 100 yards to 45 percent at 3000 yards. The fluctuation of the surface‐reflected component was greater than that of the direct component and did not depend on range.