Water trams (basically ferries) sail during the summer season departing the quayside near the museum ships in Gdynia. In Gdynia tickets can be bought from the ticket offices in the large building next to the ferry stop. Sailings marked R are subject to demand. Be warned that tickets, especially for the first sailing of the day to Hel, are very popular and you'll need to be there at least half an hour before the tram sails most days to start queuing.