

The North Sea is one of the cleanest sea areas around the coasts of Europe. Bathing water quality is under constant monitoring. There are hundreds of kilometers of clean sandy beach with magnificent dunes where the whole family can enjoy a beach holiday, but it is important to take certain precautions.
Check where the lifeguard is - and read the instructions before staying on the beach.
So be careful when you go swimming, it can be dangerous.
A horse hole is a hole in a gully where a strong outward local and temporary current can form. The horse holes occur when there is sufficient water within the rift which creates a pressure that creates an outward flow through the rift.
Bathers will be carried by the current into deep water at a horse hole. The current is so strong that the instinctive thing to do is to swim towards shore, but it is ineffective. Instead, you either have to swim along the coast, so you get away from the outward current, or simply stay afloat.
It is a coincidence that bathers will be able to be sucked under the water in the horse hole, but you are surprised that it suddenly becomes deep and by the strong outward current.