Charybdis (whirlpool)

In Greek mythology, Charybdis was a dangerous whirlpool, lying on one side of a strait across from, but near, the sea monster Scylla; both hazards are mentioned in many ancient Greek and Latin writings that involve sea voyages. Boats navigating the strait could avoid either monster but not both. From this came the saying "to be between Scylla and Charybdis", which implies that one can avoid immediate danger only by making an unwanted, long detour through uncharted waters. The saying corresponds (though not perfectly) to the English figure of speech "to be between a rock and a hard place".