But by time the ship docked less than two hours later, the UK was out, its 47-year membership of the EU now a thing of the past.
Because of Brexit, this particular crossing of the English Channel felt like crossing the Rubicon. The Cote des Dunes ferry was about midway through its journey from the French port of Calais to the English harbor of Dover when the EU shrunk from 28 members to 27 — at 11 p.m. on Friday in Britain, midnight in France.
That transition turned this otherwise wholly routine passage into something remarkable, even poignant, more of a journey from one dimension to the next than just one of many trips that cross-Channel ferries make every day.
"It's a very strange day. It's a very sad day. It feels like the end of an era, really. It feels like a step into the unknown," said passenger Audrey Sentinella, who was heading home to Britain from her job managing a care home in Switzerland.
"Even though the EU has its flaws, I feel that we are better standing with Europe," she said.
There was zero fanfare aboard at Brexit hour. Many passengers were snoozing. There were no takers in the canteen for the "Great British fish and chips." The ship's captain, Antoine Paquet, said: "It's business as usual. Concretely not much changes."
Still, passenger Alessio Bortone said he felt depressed by the possibility that traveling back and forth between Britain and the continent will become a headache after the post-Brexit transition period, during which not much is meant to change.
The Italian, who described himself as "European and proud of it," lives in Britain with his British wife and their children who are now all getting Italian passports, so travel in Europe will remain hassle-free for them.
"A lot of people losing the ability to move freely across 27 countries, it's depressing," he said. "Just this afternoon, I was traveling back from Germany and, you know, you cross four borders. You don't even think about it. From the Netherlands, Belgium, France, you just cross."
"Walls are going up instead of going down," he said.
German passenger Mohammad Dawood Majoka said Brexit felt like saying goodbye to an old friend and he was "a bit sad" to be aboard one of the first boats to dock in the newly divorced Britain.
A Muslim, he also said he fears that Britain is becoming less hospitable for foreign visitors and that Brexit is an expression of "xenophobia."
"We have a lot of populism going on, not only in Europe but also across the Atlantic and elsewhere," he said. "This is not a good sign for the future."