I always go to a village called Oostvoorne (30km SW from Rotterdam) It's on the beach which you can reach by car (you can even park on the beach) It has normally west winds, which is good for that spot. The sea is not that deep, about 500m till 1,5 meter or so.
The forecast for the coming days: monday 6-7 Bft and later 5 Bft. Tuesday: 4 Bft or so. You can visit http://www.waterland.net
and than bulletins and than 'kust meerdaags'
Have a lot of fun and a lot of wet suits because it's freezing (maybe you can better bring your ice-skates...)