Hello Peter,
Good to see Swallows coming to the Netherlands! The Dutch and German Wadden Sea is ideally suited for our kind of boats. Which islands do you have in mind? My favourites are Ameland and Schiermonnikoog, as the eastern part of the Dutch Wadden sea is " dryer" as in more shallows and creeks. And more associated wild life such as seals.
I would avoid sailing to the North Seas, as the channels between the islands can be rough, with strong currents, sand bars and breaking waves.
Where are you planning to launch?
I would be happy to give you more (sources of) information,
Peter T