If you want to travel to the UK by ship, I recommend Norfolk Lines. They cross from Dunkirk which is 40km closer than Calais and are quite a bit cheaper than P&O Ferries.
They offer restaurants and bars, children's play areas, a beautician, 10 minute massage, shops and a first class lounge.
Right now, they are offering Dover - Dunkirk Short Break Fares from £32* return. Valid for new bookings travelling before 17th December 2009.
To visit the Norfolk Line website, go here:
Ferry to France
Ferry booking to France and Ireland. Norfolkline's cross-channel ferries to France from Dover to Dunkerque
Norfolkline ferries to France, Ireland, & Scotland with Dover - Dunkirk, Liverpool - Belfast, Liverpool - Dublin, & Rosyth (Scotland) - Zeebrugge (Belgium) ferry crossings offer low ferry fares and convenient schedules. Norfolkline are the fastest growing ferry operator across the channel. So, for channel crossings, ferries to Ireland, or ferries to Belgium there's no better way than with Norfolkline.
Visit Living in Belgium for what's on in Belgium.