The myth has Charybdis lying on one side of a blue, narrow channel of water. On the other side of the strait was Skylla, another sea-monster. The two sides of the strait are within an arrow's range of each other, so close that sailors attempting to avoid Charybdis will pass too close to Scylla and vice versa. The phrase "between Scylla and Charybdis" has come to mean being in a state where one is between two dangers and moving away from one will cause you to be in danger of the other. "Between Scylla and Charybdis" is the origin of the phrase "between the rock and the whirlpool" (the rock upon which Scylla dwelt and the whirlpool of Charybdis) and may also be the genesis of the phrase "between a rock and a hard place".