New technologies have improved the accuracy of current studies. Aqua Survey deploys sophisticated equipment such as Acoustic Doppler Current Profilers (ADCPs) or electromagnetic current (EM) meters to monitor current speed and directions. ADCPs can be used to collect current speed and direction throughout the water column, while EM meters work only at one specific depth. Current data can be collected at any water column depth and is used to collect data offshore, near-shore, in estuaries, rivers and lakes. Either type can be deployed for long term observations or "dipped" for a real-time look. ADCPs can collect surface to bottom data when towed or attached to a vessel or mounted on the bottom looking up. (con't).