You can also take the eurotunnel with your bike in the Shuttle and ride down to say Dieppe or Le Havre, or up to some harbour in Belgium or the Netherlands (surely there's one).
Further West there's a ferry to Roscoff too (though it is from/to Plymouth), and you could also throw in a hop on Jersey/Guernsey?
Thanks, some great suggestions! Portsmouth is the easiest train/ferry port for us on the SW side of London but as you say, must be lots of ways across that I'm just starting to discover.
A ferry from the East coast to Hook of Holland could open up some routes too, like the EuroVelo.
You can also take the eurotunnel with your bike in the Shuttle and ride down to say Dieppe or Le Havre, or up to some harbour in Belgium or the Netherlands (surely there's one).
Further West there's a ferry to Roscoff too (though it is from/to Plymouth), and you could also throw in a hop on Jersey/Guernsey?