A whirlpool is a body of swirling water produced by the meeting...wikipedia - 01 Oct 2015
A whirlpool is a body of swirling water produced by the meeting of opposing currents. The vast majority of whirlpools are not very powerful and very small whirlpools can easily be seen when a bath or a sink is draining. More powerful ones in seas or oceans may be termed maelstroms. Vortex is the proper term for any whirlpool that has a downdraft.