Krakow to Helsinki:

How much time do you have? How much money.

Easiest is to fly. In Krakow, stay at the Sheraton - nice hotel and nice location. In Helsinki, any of the scandic hotels will be fine.

Suggest you fly - alternative may be to travel through Lithuania, Latvia, Estonia and then take the ferry from Tallinn to Helsinki. Not sure if there are any sea options from the Polish ports to Helsinki.

Thanks! We'd been thinking about flight and the Tallinn-Helsinki ferry. You've confirmed our thoughts!

Before you decide on the Tallinn-Helsinki ferry, investigate the hovercraft. When I took it from Tallinn several years ago, it was cheaper and faster than the ferry.