A new instrument for the measurement of vertical currents in the ocean

A neutrally buoyant instrument able to measure and record vertical flow, water temperature, and pressure at any oceanic depth for extended periods is described. Principles of operation, design of the measurement, recorder, recovery, acoustic telemetry, and relocation sub-systems are discussed. Special features of the electronic design are very low power consumption and circuit flexibility to adapt the instrument to a range of oceanic experiments.