Stena Line ferries from Karlskrona, 500km south of Stockholm, arrive at the Gdynia ferry terminal. From Gdynia ferry terminal, take buses 133 or 119 to the centre (ticket costs 4.80zł; from the driver 6zł). Walking to the centre of Gdynia is not out of the question, and is about 1.5km and reasonably flat. If arriving by car you should follow the signs for Centrum which will bring you to the centre of Gdynia in about 10 minutes.