On the above coordinates, you find a giant red light buoy.
Now you're at the right spot for this webcam that takes a picture.
Enlarge webcam “HAVENKWARTIER ZUID” to full screen with the icon right below in the stream:
Now you need someone to save the picture of yourself taken by the webcam or save it as a screenshot on your smartphone.
To log this cache, you have to post this picture.
Wait until the webcam is in the right position and then take the screenshot
The picture should allow to identify you as a geocacher.
How you do that is up to you, if you want:
holding up an umbrella, banners, warning vests, balloons, headlights, or cheering into the camera... be creative!