We describe a “careening” car as one that lurches or swerves from side to side in a dangerous manner, because the word careen is the nautical term for keel.
Sailing ships leaning precariously while sailing into the wind must careen or steer from side to side.
These ships needed to have their bottoms repaired regularly and scraped to rid them of barnacles.
When no dry dock was available, the captain would find a suitable beach, then run his ship aground at low tide.
The vessel was then “careened” or tipped over, exposing the keel and allowing sailors to clean and restore one side of the hull.
Once both sides were finished, and the tide returned, the ship would float off the beach and sail back to sea.