Travelling by boat it should be the destination
If you have the luxery to travel around The Netherlands by boat (actually the best way besides the bicycle), Willemstad should definately be one of your destinations, if not THE destination. It has a fine marina that offers immediate access to the town itself.
Hopelessly far away for non-car-users
Public transport in these parts of the province of Northern Brabant is rather bad. Only by bus you can reach Willemstad and it doesn't run that frequently from a relatively far away trainstation (Zevenbergen). By car it's little better, but still for the mayority of the Dutch, quite a long drive.