Whirlpool

Whirlpool, a circular current in a river or sea, produced by opposing tides, winds, or currents. It is a phenomenon of rare occurrence on a large scale, but illustrations in miniature may be noticed in the eddies formed in a river by means of obstacles or deflections. The two celebrated sea-whirlpools Charybdis (see SCYLLA) and Maelström (q.v.) are now known to be merely 'chopping seas, caused by the wind acting obliquely on a rapid current setting steadily in one direction while the tide is flowing, and in the opposite direction when it is ebbing. During calm weather neither of these so-called whirlpools is dangerous for large ships, but when the current and the wind are strongly in opposition the broken swell is so violent and extensive in the Maelström as to founder large ships, or drive them against the rocks. Though in neither of these two cases, formerly so much dreaded, is there any vortical action, instances of such action do actually occur in various localities, as in the whirlpool of Corrievrekin (q.v.), and in some eddies produced by opposing winds and currents among the Orkney Islands.