What is the name of the whirlpool opposite Scylla?

Charybdis is the whirlpool opposite Scylla in the Odyssey.

The two dangers occupy opposite sides of a narrow channel. Charybdis repeatedly swallows and expels enormous quantities of seawater, creating a vortex capable of dragging ships beneath the surface. Odysseus is told that steering too close to her could cost the lives of his entire crew.

He therefore chooses the route near Scylla, who snatches six sailors from the ship. Later, after his crew has died, Odysseus is swept back toward Charybdis on a raft. The whirlpool swallows the raft, but he survives by clinging to a fig tree until the water releases the wreckage.

The phrase “between Scylla and Charybdis” comes from this episode and means being trapped between two comparably dangerous choices. Ancient writers associated the mythic passage with the Strait of Messina, although the real currents there are far less supernatural or destructive.