The SonTek/YSI ADP (Acoustic Doppler Profiler) is a high-performance, 3-axis (3D) water current profiler that is accurate, reliable, and easy to use. The ADP uses state-of-the-art transducers and electronics designed to reduce side-lobe interference problems that plague other current profilers. This allows the ADP to make the very near-boundary (surface or bottom) current measurements critical to shallow water applications. The 1.5 and 3.0-MHz profilers are available as Mini-ADPs featuring a compact transducer head designed for applications where small size is critical.