An ocean current is a continuous, directed movement of seawater generated by forces acting upon this mean flow, such as breaking waves, wind, the Coriolis effect, cabbeling, temperature and salinity differences, while tides are caused by the gravitational pull of the Sun and Moon.
RDDs - Radar Detector Detectors, All Acronyms, viewed April 15, 2017, <https://www.allacronyms.com/RDDS/Radar_Detector_Detectors>.
A radar detector detector (RDD) is a device used in areas where radar detectors are declared illegal. Radar detectors are built around a superheterodyne receiver, which has a local oscillator that radiates slightly. It is therefore possible to build a radar-detector detector, which detects such emissions (usually the frequency of the radar type being detected, plus about 10 MHz for the intermediate frequency). Some radar guns are equipped with such a device.