I'll be going to Hamburg soon, as it happens, and it really disappoints me that there is no ferry service from anywhere in Britain to Hamburg. In fact, there are no ferry routes between the UK and Germany at all; the only one going vaguely the right direction arrives in the Netherlands.

Getting from Britain to mainland Europe by sea isn't cheap: ferries from Plymouth to Roscoff are usually over €200 each direction, no meal, no cabin, no car - one adult. And the ships are so massive that it cannot be for anything but artificial scarcity; I'd estimate you could fit about ten thousand people on one of their ships before it would begin to feel crowded.

An affordable ferry with a cabin would allow me to set off at noon, cross Britain from west to east, spend the night crossing the North Sea and arrive refreshed the next day in Bremen/Hamburg ready to use a Deutschlandticket or similar to continue by rail within Germany.

What I have chosen to do in the absence of such a service is purchase a €200 Interrail ticket for 4 days, reserve the Eurostar (Channel Tunnel) train for €60, and reserve an extra night at a hotel in Belgium for each direction. End result: a total of more than €500 and 36 hours travelling.

It's not easy being a climate-conscious traveller.