At what wind force is the ship not allowed to leave harbour?

Answer:

With a view to the safety of the passengers and crew, most ships sailing the Waddenzee and IJsselmeer will remain in the harbour at wind force 7. In consultation with the skipper you may go out on the water if you wish, but the final decision always rests with the skipper. Note that you do not always have to sail out to open water from our home harbours Kampen and Makkum. At high winds the inland waterways, with more moderate waves, offer an excellent alternative.