From Dover (UK) to Calais (France) by ferry. Route to avoid the expensive Eurostar train. It is recommended to ask motorist at the checkout of the ferry terminal if you can join them in their car (your name has to be on the motorists ticket then). Tickets for foot passengers became prohibitively expensive. The motorist usually has no extra costs with one person more or less in the car. From Dover station to Dover harbour (Eastern Docks): - by foot (30 minutes) - by bus (GBP 2) - by taxi (GBP 10) From Calais harbour to Calais station: - by foot (30 minutes) - by bus (EUR 2) - by taxi (EUR 10)
P&O Ferries / P&O
One-way - no discount for Interrail travellers: EUR 32.
It is reported repeatedly that the the former Interrail discount is still available directly in the ferry terminal and tickets are much cheaper then. However, it was never officially confirmed.
The cheapest way is to ask motorists if you can join them.