Seven nights between Southampton and New York with no ports, no islands, and nothing to look at but water. On paper this sounds like the most boring holiday ever devised. In practice it is the single most restful week I can recommend to anybody.

Something happens on a crossing that does not happen on a cruise. There is nowhere to be. No excursion to make, no tender to catch, no alarm. You read, you eat, you go to a lecture, you dress for dinner, you sleep. By day three most people have stopped checking their phone because there is nothing on it that matters out there.

Children handle it far better than parents expect, provided they are the sort who can occupy themselves. The families we book on crossings report the same. There is a planetarium, a proper library, deck space, a pool, and a kids club, and the sheer novelty of being in the middle of an ocean carries a lot of days.

The kids club is well run and staffed by British nannies, and there is proper provision for under-twos, which is unusual at sea. Nursery care is a real service here rather than an afterthought.

The number of children varies hugely. School holiday crossings have plenty. A February crossing has almost none. Ask before you book, and mean it.

What children get out of Cunard is different from what they get out of a family line. It is not adrenaline. It is the experience of being somewhere formal and grown-up and being expected to rise to it, which is a genuinely valuable thing for a child and almost impossible to buy anywhere else.

The Atlantic in winter is rough. Genuinely rough. The ships are built for it and handle it beautifully, but if anyone in your family is prone to seasickness, take that seriously and come prepared.

It is expensive relative to mainstream cruising, and the drinks are not included.

And it is a slower, quieter, more formal experience than most people are used to. That is the product, not a flaw, but it is not a holiday for a family that wants a lot happening.