even keel

Noun

even keel (plural even keels)

1. The situation in which a watercraft is floating or proceeding in a smooth and level manner.
   • [T]he rude winds died away; and gradually a light breeze sprang up directly aft, filling out every sail, and wafting us smoothly along on an even keel.1855, Washington Irving, “The Bermudas”, in Woolfert’s Roost and Other Papers
2. (idiomatic) Of an emotion or state of mind, the state or characteristic of being under control and balanced.
   • The disease . . . plays havoc with mood, personality, perception and thought, and can require constant adjustments by friends and relatives just to keep life on an even keel.2007 December 26, Denise Grady, “Coping With Alzheimer’s: Disease Brings Drastic Changes to Patients, and Stress to Family Members”, in New York Times, retrieved 14 Dec 2013
3. (idiomatic) Of a business or other activity, the state or characteristic of being well controlled and running smoothly.
   • Wall Street was on a fairly even keel Tuesday morning but the same could not be said for Best Buy as the company's stock plummeted.2010 December 14, Steve Schaefer, “Stocks Stable, Best Buy Battered”, in forbes.com, retrieved 14 Dec 2013