Its very easy on the london newhaven dieppe paris journey, if a bit lengthy depending on the ferry times you chose.
No bike box, just rock up and attach on the ferry. The paris -dieppe - paris train journey can also be without bike booking as they are regional trains : paris -rouen and rouen - dieppe and vice versa.
on the way out there is a 11pm night ferry which i usually take. on the return there is a 5pm one that arrives at 10pm in newhaven, just in time for late trains from brighton. depends if you want to ride the london-newhaven or dieppe-paris stretches.
Its very easy on the london newhaven dieppe paris journey, if a bit lengthy depending on the ferry times you chose.
No bike box, just rock up and attach on the ferry. The paris -dieppe - paris train journey can also be without bike booking as they are regional trains : paris -rouen and rouen - dieppe and vice versa.