Wake up in Norway on a ship that left Denmark the night before

A ship leaves Copenhagen in the afternoon and ties up in Oslo the next morning, and the whole sea in between happens while everybody on board is asleep. Seventeen and a half hours, one night, two capitals, and nothing required of anyone for any of it.

It goes out north with Copenhagen still in the window, and then into open water. The cabins have bunks and a bathroom. Dinner is a buffet, there is a pool on deck, a shop selling perfume and toys off the same shelf, and a room with music in it for anybody not ready for bed. Around midnight there is nothing outside at all: no coast, no lights, nothing but black water going past in the dark.

The morning does the work. There is land on both sides again, low and wooded, and it belongs to a different country, which is the entire point of the exercise. The Oslofjord narrows slowly, islands and boats and wooden houses at the water's edge, and a city arrives slowly enough to be watched arriving.

The night is spent crossing the Skagerrak, which is 240 kilometers long and between 80 and 140 wide, with the Norwegian Trench under it going past 700 meters deep. A scheduled overnight sailing between Copenhagen and Oslo has run since 1867.