What is the best way to get from England to Belgium. I want to consider ferries and trains but not air.
Best is always relative to different people. Assuming near London and wanting to go to Brussels. For us, we would use the Eurostar from London to Brussels. Booked well in advance the tickets can be almost cheap. If in northern England, then maybe one of the discount airlines.
We thought about flying but how much in advance should we book for the best fares?
For the discount airlines like Ryan airline -- earlier the better but remember their extras fees can be extensive so plan accordingly.
To get the best fare on the Eurostar from London to Brussels, book well in advance (up to 120 days allowed) at www.eurostar.com. Your ticket will include the ABS (any Belgian station) feature which will allow you to continue on from Bruxelles-Midi to any station in Belgium on Belgian trains at no additional charge.
Folks, OP said no air. Tim, I'm afraid any Belgian Station is a thing of the past. Something like either £7.50 or €7.50 extra now. Either way still a great value.