Clearwater has developed a high data rate system for drifters integrating extensive subsurface observations. The first ClearSat-HDR system was built for Dr. Luca Centurioni at the Scripps Institution of Oceanography and integrates a Nortek Aquadopp into a Clearwater SmartSensor thermistor string consisting of 20 nodes measuring temperature and pressure. The Aquadopp and SmartSensors are interrogated every 90 seconds. Data are accumulated in the surface host and 6 KB messages are sent to the user every half hour using inexpensive Iridium RUDICS. The ClearSat-HDR system can be configured to collect subsurface data from any instrument with a serial interface. The data communication system also is compatible with surface applications producing volumes of data approaching 500 KB per day.