Lookin to go on an overnight cabin to Stockholm from Turku, Finland on July 15th with a Eurail pass, but you need 4 people to do that for free Anyone else headed in that direction?
It looks as though you'll be put into a Tourist II class cabin that has 4 bunks - it doesn't necessarily mean that you need 4 people in order to get a bunk. It'll be like hostel accomodations on the ship. Information was taken from http://www.eurail.com/1_pass_benefits_finland
My suggestion to you is to call Tallink/Silja Line or e-mail them and ask them. After all, it says reservations are required for night sailings.