Hi Rolf,
if you go to The Netherlands, you probably go by the ferry Oslo <=> Kiel? In this case, the local Hobie- and Nacra/ Infusion dealers might be from interest, and you can make a VAT-deal. Both are about one hour drive from the harbour:
http://www.lindstaedt.com/gebrauchtboote.phphttp://www.sportmohr.de/main.php?sub=Gebrauchtboote&mp=Hobie&extra=Tiger
