the.com/on an even keel

Steady enough that nobody's checking for icebergs.

means In a stable, balanced state—emotionally settled or running smoothly without upset.

from From sailing: a ship's keel is the long spine running along its bottom, and when a vessel sits 'even' on its keel, it's balanced upright in the water rather than listing to one side. By the 1800s the phrase had drifted ashore to describe steady nerves, steady finances, steady anything.

origin
keel is the ship's spine, balance literally prevents capsizing
first use
nautical term since the 1600s, metaphor came later
modern use
describes finances, emotions, or shaky governments staying upright
irony
usually said right before something tips over
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