Just had a quick peek for you - a return route...now I dont know that dates you want to travel, and this is without a cabin, only a reclining seat which might not be what you ar elooking for on a journey this long but....
Route Details
The total price of your tickets will be
175.00 GBP Route 1 - Route Details
Route 1 : Plymouth to SantanderDeparture Date/Time:Sun 04 May 2008 at 1600Arrival Date/Time:Mon 05 May 2008 at 1230Passengers: 1 Adult Transport: Motorcycle
Accommodation:1 of Reclining Seat
Route 2 - Route Details
Route 2 : Santander to PlymouthDeparture Date/Time:Thu 15 May 2008 at 1500Arrival Date/Time:Fri 16 May 2008 at 0930Passengers: 1 Adult Transport: Motorcycle
Accommodation:1 of Reclining Seat