water safety 

The ocean is beautiful, but do not forget it is still nature and sometimes can be unpredictable and rough. 
Close to the shore, you have rip currents. These are strong channels through which the water that came from the ocean, goes back to the ocean.  Be careful with these, as they can easily swipe your feet off the sandbank and take you towards the  open ocean/sea. In these situations, it is important to stay calm and not panic. Instead of swimming against the current towards shore, let the current take you a little further and swim parallel to the shoreline. Once you feel that the current is getting weaker,  it will be easier to swim back to the shore.

In the summer months, there are lifeguards that surveillant the beach in most locations of the Netherlands but in Winter, Spring and Autumn you are own your own. Be extra careful since those rip currents are a very common perilous situation along the Dutch coas
For more information and safety matters consult  https://www.knrm.nl