This photo is from a cruise that I took from Rostock, Germany to Helsinki, Finland. If you have a Eurail Pass it will cost you 66 Euros for a seat. The ride is ~2 days or so and a room would be recommended. I got lucky and met some nice ladies while waiting who offered to let me sleep in their cabin with them.
Considering I had spent the previous night sleeping on the street in a sleeping bag liner, under a shrub, it was kinda like heaven. The cruise is really nice and has lots of dining options. I brought a lot of my own food on as I knew it would be really pricey. These cruises are fun but mainly truckers and what not. The Helsinki -> Stockholm is a different story though.
Note: To see the image larger, right click “view image”.