In 1997, Dr. Williams identified a need in the oceanographic community for a small, affordable, easy-to-use current sensor that can measure currents and turbulence. By keeping the cost down and the size small, it was predicted that arrays of current sensors could be deployed to measure flow fields, improving on previously used time series of currents at one or two points. Such an array would be of great benefit to the measurement and understanding of organized structures, such as Langmuir cells. In order to meet the aforementioned objective, NOBSKA Development Corporation, formed and developed a Modular Acoustic Velocity Sensor (MAVS), a three-axis current meter that measures differential-acoustic-travel-time in a small measure volume. It is a derivative of the Benthic Acoustic Stress Sensor (BASS) with the following requirements: low cost, small size, high accuracy, good cosine response to current direction (immunity to off axis flow and gain independent of attitude), lack of bias in a wave environment (no wave rectification), ability to measure turbulence and the Reynolds stress (the turbulent transfer of momentum), resistance to fouling (helped by no moving parts), ability t