IN A MARINER'S WORDS
"vEILLER AU GRAIN"
The fox might attack the chickens at night, but we’ll keep an eye on things and prevent that.
The expression “veiller au grain” means keep a close watch on something to avoid a tipping point in a situation, a possible danger or loss of control over events. In other words, whenever we should be really vigilant and careful because we want to be prepared for any eventuality.
The “grain” in the expressions has nothing to do with agri-food. It actually refers to a marine reality. For seafarers, “le grain” is a sudden, extremely powerful storm gale, a whirlwind that forms out of the blue and messes up ship manoeuvres. It doesn’t last long but it can do damage. That’s why mariners stay vigilant to be ready to react like clockwork. In short, they keep a close watch on the wind. Use of the expression “veiller au grain” aboard ship can be traced back to around 1830.