Some measurements with instrumented neutral floats

The motions of instrumented neutral floats were measured during short tests at various locations in the North Atlantic Ocean. The vertical paths as a function of time were obtained for floats from the time they were placed in the water until well after they reached their equilibrium levels. Motions attributed to internal waves were observed on sensitively instrumented near-surface floats. Pairs of floats were found to separate rapidly with a speed which was not constant.

A pressure-gradient measuring device showed no fluctuations over a length of approximately 100 cm at depths from 200 to 700 m. The static sensitivity of the equipment was approximately 3 dyne cm⁻² mm⁻¹. Response of the device in shallower water was probably caused by gravity waves.