This is a standard warning of floating containers off the Dutch Coast. This may well be the only public mention of these 10 shipping containers.
Quite a scary thought when you think that the sea off the Netherlands is one of the busiest shipping areas in Europe!
This is a screen shot (MarineTraffic) of all of the shipping in the German Bight at the time of typing – the ships shown are larger commercial vessels – smaller craft will not even appear! What damage could these floating containers do?