RD Instruments Inc, USA, (RDI) commercially developed the Broadband Acoustic Doppler Current Profiler (ADCP) in the early 1980s and has delivered more than 3500 instruments to over 50 countries, during the last 20 years. While vertical profiling from a fixed or moving platform is considered to be a standard application technique, horizontal profiling using ADCPS is only now becoming recognized as viable approach for many applications. The RDI H-ADCP instruments profile horizontally, and are capable of measuring the current field ranging from a few meters to 300 meters. Measurement of the horizontal current flow field has a variety of applications that include: (1) Measurement of discharge in rivers and channels. (2) Ports and Harbors where a pier-mounted instrument monitors shipping channels to aid navigation and safety. (3) Estuaries for defining complex circulation patterns and lateral mixing. (4) Oil platforms and rigs, and (5) Hydroelectric and tidal power plants. RDI's H-ADCP uses patented Broadband signal processing to obtain the best combination of range, resolution and data quality. The new system measures water velocities up to five meters per second at as many as 128 individual points, centered at one depth. Field results from a wide variety of sites will be presented.