Whirlpools

found: Glossary of hydrology, 1998:eddy (a circular movement of water that is generally in a different direction from that of the main current; it is a temporary current, usually formed at a point at which a current passes some obstruction, or between two adjacent currents flowing in opposite directions (cf: whirlpool, maelstrom) whirlpool (a body of water moving rapidly in a circular path of relatively limited radius (cf: eddy; maelstrom)))

found: Eapen, P.K. Elsevier's dict. of fisheries, 1999:eddy (1. wind or water moving in a curved or circular direction; 2. current or water running in a direction contrary to that of a tidal stream; whirlpool (current that has a rotary motion over a comparatively small area))