Deutsche Bahn travels directly to Husum intercity railway station. There you change to the regional train that connects Husum with St. Peter-Ording. The town of St. Peter-Ording has two stops, the last of which is "Bad St. Peter-Ording". As the stop is a dead-end station, you can travel comfortably to the terminus. From St. Peter-Bad station it is approx. 2 kilometres to Zweite Heimat. Taxis are available at the station. You can also take the local bus from here to the Utholm bus stop, which is directly opposite the hotel.
You can find the timetable for the St. Peter-Ording local bus here.
Do you need help with your luggage? Deutsche Bahn offers a luggage transport service for your journey. Your suitcases will be collected from your front door and delivered directly to the hotel. As soon as you arrive in St. Peter-Ording, your suitcases will be waiting for you in the room you have booked.
You can find more information here.