England, just a 2-hour boat ride from Dunkirk, is an ideal destination for a day trip or a short break. DFDS Seaways offers up to

Ferry between Dunkirk & Dover
12 departures per day to Dover. The ferries are new and comfortable and crossings can be offered at very attractive fares.
Reservations are made from the website https://www.dfds.com/
A cruise on the English Channel from Dunkirk: the best way to start your trip to England.