Large signs point out danger
It is a life-threatening misconception that bathing is not dangerous between the Rhine tributaries. The Rhine is a busy waterway for freighters and tankers. The water displacement of passing ships creates suction effects even near the banks. At the tips of the cribbles, dangerous whirlpools can pull people down.
The city of Bonn warns of the dangers and points out with large signs: "Swimming in the Rhine is life-threatening!". This is what you read on the banks of the Rhine in Beuel, Bonn and Bad Godesberg: "Do not swim in the Rhine, no matter how tempting it may be. Keep an eye on your children so that their 'beach vacation' on the Rhine doesn't end in tragedy. Remember that waves generated by ships can have a strong suction effect." To make even more people aware of the dangers, for example foreign-speaking visitors*, the text is now also written in English on the newly designed signs.
Current pulls people along
It is often underestimated that the boundary between standing and flowing water is not slow, but occurs unexpectedly. Where the bottom drops steeply to the shipping channel, you suddenly lose the ground under your feet. As the water level falls, the boundary to the navigation channel becomes smaller and smaller, and the distance to the ships dwindles very quickly. In the urban area of Bonn, the Rhine flows at a speed of about six kilometers per hour. The flow speed can increase significantly during high water. Even experienced swimmers cannot withstand this current for long.
Suction effect of vessels
Ships make their way through the water, pushing waves in front of the bow. Behind them follows a large negative pressure area. This negative pressure is followed by large stern waves. The waves generated by the ship develop a dangerous suction effect. They can sweep bathing children out of the protective area between the cribs and into the current. The next suction wave is created when the waves run back out of the cribbing area. If children run after the sinking water level during the suction effect of the ship, they will be caught by the following wave, washed over and carried away. The closer, faster and larger the ship, the greater the dangers.