Who are the biggest stumblebums of the Dutch waters? Fishermen? With those dangerous fishing nets? Kite surfers? In any case life-threatening, so that should be forbidden anyway ;-) Speedboats? That kind of people are always navigating with their Tomtom on the water, right? Or would there be another group of water sports enthusiasts that should actually enroll in a Coastal Navigation course themselves?
It turns out that the largest group of stumblebums are actually the sailing yacht owners on the IJsselmeer and North Sea. And without any doubt actually. It is those sailors, with their yachts stuffed with the most advanced navigational equipment, that force the courageous men of the Dutch Coastguard to leave their warm beds and loved ones to voluntary head to the cold sea, at night.
Because "that sandbank was not on the map, once again". Right...?